Dayton RS WMTW Center & TMWW Mains

[kgveteran]

The resistors : 004-1 1ohm $1.25
004-4 4ohm $1.25
004-25 25ohm $1.25
004-10 10ohm $1.25

Caps are Dayton also, 027-430-12uF $3.55
027-436-20uF(2) $4.95ea.
027-432-15uF $4.10
027-410-1.0uF $1.15
027-428-10uF $3.15
027-447-100uf $19.51
027-434-18uF $4.65

Coils: 255-026 .25mH Janzen 20ga. aircore $1.94
255-250 1.0mH Janzten 18ga. aircore $4.41
255-230 0.5mH Janzten 18ga. aircore(2) $3.09
266-924 4.7mH Erse 16ga. ironcore $14.76

------------
$78.28


I used Dayton terminal plate 091-610 $9.75 (double binding post)
Binding posts 091-624(2) $19.90 (for both sets)


The midrange XO requires a 38uf cap.I used a 20uF and a18uF in parallel. It also reqired a resistor value of 35ohms, so I combined a 25ohm with a 10ohm in series.Watch the positioning of the coils.There is a great link to assist you should you choose to mount them like I did. Good luck :)


(2) RS225's $43.45 each (295-366)
RS150 $28.55 each (295-362)

RS28as-4 $49.45 each (275-135)

[Dougie085]

hmm....is there a parts/cost list for the tower? lol are they pretty much the same as the center? i was thinking about building the mudula mtm's or natalie p's anyone compared these to them? i kind of want floor standing speakers....so ionno =/....and this center just looks awsome :) lol

[dawaro]

So far a finished tower design has not been published. Dennis is close to finishing his design but has not published it. I have sent the measurement files to Jon, Curt, and Chris but I have not heard anything from them yet. Everyone is facing the same problem, too much to do, to little time to do it.

[Dougie085]

yea i think thats always a problem for everyone unfortunately....

[Curt C]

So far a finished tower design has not been published. Dennis is close to finishing his design but has not published it. I have sent the measurement files to Jon, Curt, and Chris but I have not heard anything from them yet. Everyone is facing the same problem, too much to do, to little time to do it.

David,

I have the measurements you sent, but unfortunately have been busy with previous commitments. I am just finishing up a 3 way with Accuton woofer and mid, and an OW1 tweeter. These are very impressive drivers, -too bad they aren’t mine.

Designing your tower Xo shouldn’t be a labor-intensive issue, as I’ll hopefully be able to modify the topology of the center channel version to suit. I won’t know for sure until I try it though…

Next up on my plate, well, not counting the other ‘little projects’, is my version of an all RS 3 way. Like your design, it uses the RS28A and a pair of RS225’s per side, but I chose RS180 for a mid. This is a ‘2 box’ design with the TM residing in a 17” dia. sphere, while the WW’s will be situated in an oddly shaped ML TQWT enclosure. This will be one of those ‘love it or hate it’ designs, and certainly will offend the aesthetic senses of some. I will make the plans and crossover network available for those brave souls who have eclectic tastes, and have nothing better to do than attempt to make big hollow balls out of sheets of MDF…

C

[kgveteran]

I should have a stereo pair in about 3 weeks.

[Jim Holtz]

Dennis has officially signed off on the RS 3-Ways he's been working on. I have the crossover, BOM and sealed cabinet cut list for the Seas 27TBFC/G (H1212) version.

I decided to follow Dawaro's lead and post the crossover, BOM and cut list next to the RS version he posted so they'd be together. The cabinet I have listed is a sealed version which would of course work with either tweeter as would his ported version. The sealed version has the same front baffle dimensions but is 13 1/4" deep. Depth could easily vary a 1/2" depending on what works for you. Ignore the driver placement on this cut list. It is a dimension and quanitity cut list only. The driver placement image is shown three posts below. Not shown in the cut list is the sub enclosure for the RS150. It should be about 5 liters internal which works out to about 9 liters external. Internal dimensions are 6" H x 6" W x 11 1/4" D.

I've also revised the BOM for Dayton caps and Eagle resistors to lower the price of the crossover by about $40. The original BOM with Jantzen caps and Mills resistors is 3 posts below with the driver location image and FR graph.

Jim

[dawaro]

Here are the files for the RS28A networks.
From talking to Dennis he feels that the sealed version is quite a bit smoother than the ported. Although he did note that it may have been due to the test box not being ridgid enough.

The final box size esternal dimensions are 10.75 w X 42 h X 21.5 d, Internal are 9.25 w X 40.5 h X 19.25 d.

The enclosure for the RS225's is 108 liter / 3.814 ft tuned to 27.29hz with a 4" port 9.2" long. Using one of the 4" PSP flared ports would be the best here. The result is an F3 of 28.05hz.

Attached are also cut list for a PAIR of towers. There is one cut list for a 4 X 8 sheet and one for a 4 X 4 sheet.

Make sure you check the math before you cut anything, I have been known to make mistakes in the area before.

[wrz0170]

Please pardon the neophyte question regarding the inductors. :B

The listed inductors on the schematics have just the "mH" values, no DCR(ohms) values after that. Should I just look for the given mH value?

Thanks!


Here are the files for the RS28A-S networks.
From talking to Dennis he feels that the sealed version is quite a bit smoother than the ported. Although he did note that it may have been due to the test box not being ridgid enough.

The final box size esternal dimensions are 10.75 w X 42 h X 21.5 d, Internal are 9.25 w X 40.5 h X 19.25 d.

The enclosure for the RS225's is 108 liter / 3.814 ft tuned to 27.29hz with a 4" flared port 9.2" long. The result is an F3 of 28.05hz.

Attached are also cut list for a PAIR of towers. There is one cut list for a 4 X 8 sheet and one for a 4 X 4 sheet.

Make sure you check the math before you cut anything, I have been known to make mistakes in the area before.

[Jim Holtz]

William,

I asked Dennis the same thing when I was creating the BOM. He said to consider the DCR of an inductor if the resistor next to it was less than .5 ohms. If the resistor next to the inductor was .5 or greater, it really is a resistor. He also said to use the DCR as a guide and get as close as possible with out obsessing over it. Close is Ok. Dennis indicated the 3.0 inductor on the woofer would benefit from being a low DCR variety so I speced a steel laminate in the BOM for the H1212 version.

(edit)
I'm adding a couple more files for the RS 3-way that my previous post wouldn't allow. Follow the driver layout Dawaro specified in the gif I'm attaching. I'm also attaching the on axis FR graph Dennis measured for the RS 3-way Seas 27TBFC/G version in his test cabinet. The original BOM with Jantzen caps and Mills resistors is attached to this post now and a new economy BOM with Dayton caps and Eagle resistors is attached to the original post for a $40 savings.

HTH

Jim


Please pardon the neophyte question regarding the inductors. :B

The listed inductors on the schematics have just the "mH" values, no DCR(ohms) values after that. Should I just look for the given mH value?

Thanks!

[kgveteran]

Well here is the first pair.Wow do these thing image.Keep in mind they are not even close to being broke in.

I started by listening to Peter Gabriel SACD "So".Red rain was full and very clear.Don't give up was unreal.Kate Bush's voice with Gabriel was holographic.These speakers hit voices so dead on it can't be put into word.Mercy street was haunting and better than I ever heard it before.

Out in the room they need no EQing at all.I toed them out slightly and the center image was perfect.I mention EQing because I had some issues with the center channel, but it was a placement issue not the speaker.

I'm using a 100wpc B&K ST-140.Most of my listening was around the 75-85db measured with the ratshack SPL.No midrange hash or spitty tweeters and the bass from the two 225's never got in the way of the hi's and mids.

Then I got out some old CD's and listened with the bass management crossing over to the subs at 100hz (that frequecy works best).

I started with tracy Chapman Cross Roads.Becareful of my heart.........Do I have to say again how these things image and deliver vocals.OMG."All that you have is your soul"......here again.....her voice just floated between these babies.No harsh old cd sound.Very nice.

So, I'm going to take a building break and start the center in a couple weeks.These speakers make me want to listen to stereo again.Like my old Spica TC-50's.Here is a pic of them.

I'm in the middle of Harry Connick "We are in love" ."A nightingale in Berkley Square.......The upright bass is in the left corner and about as pitch perfect as could be.His voice is as nasaly as could be.Perfect.This is plain ol' CD too.These drivers are so damn clean......more to come.

[Dougie085]

who's building the towers? lol id like to see those finished :) and jim i noticed in one of your box schematics it has 2 woofers but the other has one? is that an error on the one with 1 hole? lol i would guess cause they are supposed to be TMWW just curious. im thinking about building these or possibly designing some like MTMW towers or somthing....is there a benifiet to running an MTM design as apposed to at TMWW or TMMW?

[Jim Holtz]

who's building the towers? lol id like to see those finished :) and jim i noticed in one of your box schematics it has 2 woofers but the other has one? is that an error on the one with 1 hole? lol i would guess cause they are supposed to be TMWW just curious. im thinking about building these or possibly designing some like MTMW towers or somthing....is there a benifiet to running an MTM design as apposed to at TMWW or TMMW?


Use the front baffle layout showing two RS225's on it. The cut list is only for dimensions and quantities. Which brings up another point. I use a 3/4" and a 1/2" piece of MDF glued togeter for the front baffle with the 1/2" piece on the inside. I round over the woofer holes using a 3/4" round over bit in my router or have used a saber saw to cut a 45 degree bevel in the past. The point is to open up as much as possible the area around the back of the driver to eliminate the tunnel effect. This isn't reflected in the cut list so two additional 1/2" front baffles need to be cut.

Personally, this configuration is my top choice for a 3-way. Sensitivity is good (about 87.5 per Dennis) and the imaging is similar to a M/T design so it'll be very broad and open sounding.

HTH

Jim

[Bent]

kg, that couch in the photo....
it looks like mine from the rear, does it have two cushoins on the back, but three on the seating surface?

[dawaro]

I should also mention the baffle has a 3/4" roundover on it.

[kgveteran]

It's a sofa recliner.it fits four skinny people,five very skinny kids or three full size adults.

Shervin,
PE has oodles of parts :) I can't wait to get the "center done".Sounds kinda weird looking at that array.My wife is completely confused.

KG

[kgveteran]

Wait until you see the speaker stands I'm building for the mains.My stands are too low.

[ssabripo]

It's a sofa recliner.it fits four skinny people,five very skinny kids or three full size adults.

Shervin,
PE has oodles of parts :) I can't wait to get the "center done".Sounds kinda weird looking at that array.My wife is completely confused.

KG

sure sure! :P

well, I just spoke to Kyle @PE and there aint no RS28A's right now....thanks a lot man :W

[BDixon]

Stupid question here, in the plans from dawaro it shows 15.13 and 24.88 from bottom to center for the woofers. Please tell me that 15.125 and 24.875 will work or is it really that critical?

Also dawaro said "From talking to Dennis he feels that the sealed version is quite a bit smoother than the ported". If I wanted to try sealed(already have a sealed tumult) would I just plug the port or would it require changes to the box and/or crossover?

Thanks,
Brad

[Paul H]

Stupid question here, in the plans from dawaro it shows 15.13 and 24.88 from bottom to center for the woofers. Please tell me that 15.125 and 24.875 will work or is it really that critical?




It's not that critical, nor is accuracy like that possible for most. Your numbers are fine.

Paul

[kgveteran]

Well here they are vertical.I'm starting to like em like this.

[ssabripo]

Well here they are vertical.I'm starting to like em like this.


did you notice any acoustical difference in this form vs horizontal?

[BDixon]

If you were going to put them vertical why not build the towers? I'm just curious is all or was the tower design not out when you started them?

[cjd]

You might get better dispersion with the tweeter on the outside. I would felt treat it in this case.

However, you may be able to find spots where upper midrange just seems to go away. Pink noise can identify this more easily sometimes...

C

[Dennis H]

If you were going to put them vertical why not build the towers? I'm just curious is all or was the tower design not out when you started them?

Or do a vertical WTMW if you don't want a TMWW. Putting the T beside the M horizontally is what the designers went to great lengths to avoid with the original designs -- both the center and the tower.

[kgveteran]

After listening to my usual number of CD's, I found them to sound fine.What made a world of difference was the height.Getting them up that high really got the sound stage large.

I use a number of songs, and one is Harry Connick Nightingale in Barlky square.His voice is dead center and quite clear.The bass is to the left and the sax is to the right.Peter Gabriel "So" SACD is the same.I'm sure this orientation goes against the design, but I'm going to leave them there for the time being.

As I said the speakers measure flat as a board at 1m. Like all rooms they add to the mix.I will end up fine tuning with my Ashly PEQ-66.I will soon have three of these stereo PEQ's and I'll use them in each channel.Four bands per speaker will be fine.Most adjustments are in the neighborhood of -3db, so I've got them where I want them , it's just a matter of taste at that point.

I'm looking forward to the three up front and now.......hmmm what to do for the three surround channels.I've been doing most of my listening using the rears as monopoles or direct radiators.I think I'll looking to build a twoway with either a 28a and a 180, or the 28a with a 150.My thought is a single 180 would do fine.Rear center is not as important as the two rear/side surrounds.

KG

[kgveteran]

If you were going to put them vertical why not build the towers? I'm just curious is all or was the tower design not out when you started them?

More time had been spent on the center.I figured if the horizontal config didn't work I'd stand them up and give a listen.After building the center first I felt that was the most important aspect of this project.It's a killer center.And a fine main too.

[ssabripo]

Kg, having played with these as your mains for a few days now, give me an honest opinion, as I'm doing final preparations to order everything at once:

would you think that this configuration you have sound as good as say a pair of NatalieP's or Dayton RS3-way's?
How is the soundstaging on it, specially on jazz and classical tracks, as compared to high-end mains you may have heard?
How is the depth perception?

the Center is a done deal, but you have opened up a third option for my mains, and would love to hear the feedback (yes, I've read what you posted already ;) ).... PM me if you like.

[kgveteran]

Kg, having played with these as your mains for a few days now, give me an honest opinion, as I'm doing final preparations to order everything at once:

would you think that this configuration you have sound as good as say a pair of NatalieP's or Dayton RS3-way's?
How is the soundstaging on it, specially on jazz and classical tracks, as compared to high-end mains you may have heard?
How is the depth perception?

the Center is a done deal, but you have opened up a third option for my mains, and would love to hear the feedback (yes, I've read what you posted already ;) ).... PM me if you like.

Go a head with the center and if I were you , i'd build a pair of towers. Even on their sides they still image great.But to start out building them to put them on their sides would be a step backwards.To go ahead and sell off two of these and build two towers.........it's not worth it.Go for the towers.

KG

[FroDaddy]

Also dawaro said "From talking to Dennis he feels that the sealed version is quite a bit smoother than the ported". If I wanted to try sealed(already have a sealed tumult) would I just plug the port or would it require changes to the box and/or crossover?

Thanks,
Brad

If someone gets a chance, I'd like to know also!

[Jim Holtz]

If someone gets a chance, I'd like to know also!

The crossover isn't affected by whether the cabinet is ported or sealed. I'm a proponent of sealed cabinets. They're smaller and have clean, tight bass as the expense of some low level extention.

Dennis struggled with boomy bass in the ported cabinet which could probably be corrected with sound deadning and bracing. Either way, the crossover is the same.

HTH

Jim

[kgveteran]

I currently use two of the center channel versions as vertical mains.They are sealed and very tuneful. My Tumults integrate quite well with them.

I wish I could adjust my filter slopes to match the sealed enclosures.

The vertical position hasn't caused any real problems.A little tweaking with a PEQ with very broad Q's fixed what ever the problem was.

Now I can start the "center". :)

Also my cabinets are the smaller ones 12.5"x12"x26".They look pretty cool as mains, vertically.

[ThomasW]

I wish I could adjust my filter slopes to match the sealed enclosures.Since Jim Holz's post wasn't adequate to the task, let's try again to clarify the situation.....

The design of the crossover is completely independent of the alignment of the the box. This means that sealed, ported, PR, bandpass, TL, IB, isobaric, or whatever, the design of the crossover stays the same.

Any improvements noticed with the use of EQ, is a function of the acoustic characteristics of the room placement.

[michael stevene]

hello,
i'm new here. is the back 1.25"? what about bracing placement?
thanks,
drmike

[kgveteran]

The crossover is independent of the enclosure type.The enclosure relates to the bass drivers only in this design.Sealing it off will give it a nice 12db/oct rolloff.

I would agree with Jim, I like sealed systems also, but this will be further explained... :roll:

[ThomasW]

Sealing it off will give it a nice 12db/oct rolloff.12dB/octave roll-off occurs only if the box is being used in an anechoic chamber. Anywhere else and room gain effects the roll-off, as it does with all alignments.

[Jim Holtz]

Since Jim Holz's post wasn't adequate to the task, let's try again to clarify the situation.....

The design of the crossover is completely independent of the alignment of the the box. This means that sealed, ported, PR, bandpass, TL, IB, isobaric, or whatever, the design of the crossover stays the same.

Any improvements noticed with the use of EQ, is a function of the acoustic characteristics of the room placement.

Thanks for clarifying what I was trying to convey. :D

Jim

[kgveteran]

12dB/octave roll-off occurs only if the box is being used in an anechoic chamber. Anywhere else and room gain effects the roll-off, as it does with all alignments.

So the starting point is 12db/oct, and room gain is unpredictable.

[ThomasW]

So the starting point is 12db/oct, and room gain is unpredictableWithin reason room gain is predictable. It's a bit time consuming but can be modeled using computer programs such as LspCAD, RPG Acoustics Room Optimizer, and others.....

[kgveteran]

Or as stated before, take the speaker in question, bring it out side,place it on a twelve foot ladder (quasi-4pi) and run a sweep.Then place it back in your room and run a sweep....compare the two and whala.

Running programs as in the RS tower gets you close.The bass seems to be bloated and who knows why.Theory.Theory and programs are fine but to get to the devil that is in the details you have to get down to true figures and grass roots testing.

This is fun throwing around idea's but we've split this little hair a bit close...cheers :) .

Lets get back to this great design and I hope more people get busy so we can compare notes :T .

[cjd]

whala

voilà? ;)

And, I have seen in some instances that people used to a 2-way tower will find flat bass response in a 3-way tower to be bloated, even if they're used to a sub. Not sure why. Of course, it could actually be. ;)

C

[kgveteran]

voilà? ;)

And, I have seen in some instances that people used to a 2-way tower will find flat bass response in a 3-way tower to be bloated, even if they're used to a sub. Not sure why. Of course, it could actually be. ;)

C

LOL,lol,lol,lol :rofl: As Bugs Bunny would say,"What a maroon" I will never use whala again :B .

Depending on the tuning frequency I find most ported three ways to have that sound.This three way sealed is a real winner.I wish I had a bigger room to let it open up a bit.

[GaryG]

This is a beautiful system. My wife even likes it. That means I need to start ordering the components.

What should I use for the surrounds? I could build another set of mains or even 2 center channels but I think a matching set of RS dipoles would be perfect. Any ideas?

Thanks,
Gary


;x( I'm not worthy ...........

[kgveteran]

It looks like after some playin around with the PEQ I always end up lowering the tweeters output.I ended up disconnecting both tweeters to listen to the mid and woofers.The midrange was pretty solid and there isn't a bit of harshness.

I want to avoid EQing the mid since it sounds so good with the woofers.What value resistor do I start with and how will i insert it into the tweeters XO board..I think if I tame it down a bit things will smooth out and I can get the PEQ out of the signal path.

I am using Curts XO.The tweeter starts at 1.8khz.When I adjust the EQ its usually about -6 to -9db.At the seating position that only equates to about a -4db change.

They are a little tougher to orientate in the room, but I'm back to them being horizontal.They are much smoother and when I move my head side to side The image remains constant.( I know stop moving my head :B )

KG

[kgveteran]

This is a beautiful system. My wife even likes it. That means I need to start ordering the components.

What should I use for the surrounds? I could build another set of mains or even 2 center channels but I think a matching set of RS dipoles would be perfect. Any ideas?

Thanks,
Gary


;x( I'm not worthy ...........

What did you build , the mains ? What are you driving them with ?

[GaryG]

Sorry, I didn't mean to mislead anyone but I have not started to build the speakers yet. I have spent the past 2 months trying to decide whether to build the RS 3-way system or this one and have finally decided on this one. I am about to order the drivers for the mains and the center channel and begin by building the cabinets. If I can decide what to do for the surrounds I will include those drivers in my order and have all the drivers at the start.

I am currently running a Pioneer DSX-D711 5.1 receiver (couple of years old) and some 30 year old Pioneer CS-99 speakers (100W, 6 driver, 5 way). I thought I would start with the speakers and when I am done with them start looking for a quality amp.

The system will be installed in my great room which is basically a 20' cube with several large openings.

Any input would be appreciated.

Thanks,
Gary


;x( I'm not worthy ................

[Brian Bunge]

I should be ordering xo parts soon for my center channel and had a quick question for Chris if you're out there. I'm planning on using your version of the XO since I believe you said you felt it should mate well with the my big 3-way towers. I just wanted to make sure that the design posted on page 3, post 83 was your final revision. If so, I'll start adding up the costs of the parts and see just what I have left over from the big 3-way parts.

[cjd]

Well, without listening I'm not sure I can guarantee it's a final revision. :) It's final based on the data I have at this point, and since it's a pretty sure thing we have good input data I think it's an exceedingly high chance that it will remain final.

Jon's should be a good match as well.

C

[Brian Bunge]

Chris,

Well, I think that'll be good enough for me! Thanks! All I have to do is glue in the baffle and back and then I'm ready for the crossover.

[kgveteran]

Drats...the 8" RS woofers are out of stock! I just ordered all the parts,but the woofers for my third. :cry:

[kgveteran]

Any one willing to comment on post #296 about padding down the tweeter.


I tryed to order my parts for a third and the 8" RS woofers are out of stock :cry:

[wrz0170]

Drats...the 8" RS woofers are out of stock! I just ordered all the parts,but the woofers for my third. :cry:

PE had them as a DOTD last weekend. :B At $35, that saved me $20.00 for the overall cost. I ordered my 4. Might be why they are out of stock.

Of course when I am ready to finish the rest of the shopping, they will be out of stock of something else!

[kgveteran]

Any takers on lowering the tweeters output.......hello......anybody...."crickets chirping"

[ThomasW]

Buy a variable L-pad of the proper impedance for the tweeter and wire it according to the supplied diagram.

Set it to the output level you want.

Without changing the dial, cut it out of the circuit and measure for the series and parallel resistors that will be used in the permanent network.

Here's how they're wired
http://www.uneeda-audio.com/pads/

[Rudy D]

Guys love this tread. I have taken the plunge and will build the towers -TMWW. Can someone verify some of the following cut parameters? Also has anyone created a diagran on the internal build of the towers with dimensions?
1) According to the cut sheet, There are 4 braces, how do you position them in the box? 2) One of the plans are for the ported version. 4"dia., 9.2' long. how far up from bottom should it be positioned?
3) the sub enclosure for the RS150 has internal dimensions of 6"H x6"W x11"D. Does that make the external demensions; 6.75' H x 6.75" W x 12" D?
4) Not listed on the cut sheet are the side panels. Are they 20"W x 42"L? Right now all I have done is made all the cuts in material as I understand it. Once I get these questions verified, I will order the XO parts and begin to build enclosures. any tips on building these towers would be greatly appreciated. Thanks guys great thread!

[Dennis H]

KG, Thomas's advice would be how you would normally determine the values for the series and shunt resistors in a design with an L-pad. However, if I recall, you built Curt's design with just a 1-ohm in series and no shunt. I'd try replacing the 1-ohm just before the tweeter with 2 ohms or 3 ohms or whatever it takes to pad the highs down so you like them. If that doesn't work out, do like Thomas said and remove the 1-ohm and replace it with an L-pad to determine series and shunt values.

Edit: the shunt resistor in an L-pad would be after the 1-ohm series resistor in Curt's drawing and would connect between the + and - terminals of the tweeter.

http://home.houston.rr.com/roberts17207/CC%20Dayton%20RS%20Center%20Schematic.gif

[Jim Holtz]

Guys love this tread. I have taken the plunge and will build the towers -TMWW. Can someone verify some of the following cut parameters? Also has anyone created a diagran on the internal build of the towers with dimensions?
1) According to the cut sheet, There are 4 braces, how do you position them in the box? 2) One of the plans are for the ported version. 4"dia., 9.2' long. how far up from bottom should it be positioned?
3) the sub enclosure for the RS150 has internal dimensions of 6"H x6"W x11"D. Does that make the external demensions; 6.75' H x 6.75" W x 12" D?
4) Not listed on the cut sheet are the side panels. Are they 20"W x 42"L? Right now all I have done is made all the cuts in material as I understand it. Once I get these questions verified, I will order the XO parts and begin to build enclosures. any tips on building these towers would be greatly appreciated. Thanks guys great thread!

Rudy,

Here are some pictures of how I am doing it. Exterior dimensions of the sub enclosure are 7 1/2" x 7 1/2" x 11 1/4" which butts against the back of the speaker in the sealed design I'm building. It would be 12" in the ported cabinet since it's so deep and won't come close to the back wall.

Sorry, I can't help you on the ported cabinet dimensions.

Jim

[kgveteran]

KG, Thomas's advice would be how you would normally determine the values for the series and shunt resistors in a design with an L-pad. However, if I recall, you built Curt's design with just a 1-ohm in series and no shunt. I'd try replacing the 1-ohm just before the tweeter with 2 ohms or 3 ohms or whatever it takes to pad the highs down so you like them. If that doesn't work out, do like Thomas said and remove the 1-ohm and replace it with an L-pad to determine series and shunt values.

Edit: the shunt resistor in an L-pad would be after the 1-ohm series resistor in Curt's drawing and would connect between the + and - terminals of the tweeter.

http://home.houston.rr.com/roberts17207/CC%20Dayton%20RS%20Center%20Schematic.gif

I ended up on the phone with PE and they said that a 8ohm stereo L-Pad in parallel would do the job.I'll probably mount it on the back panel since it's 3/4" there.

The value of the stereo version is (15watts X 2 = 30 watts ) for the parallel version once I solder jumpers.

Once again, the success in DIY is all the support.


KG

Quick edit: Should I leave the 1ohm resistor in place w/ the L-Pad ?

[dawaro]

I have up dated the cut list and I have thrown together a very rough layout drawing. The cut list are for a PAIR of towers. Again there is a cutlist for both a 4x4 and a 4x8 sheet.

Due to the fact I have not built the cabinet yet these are estimates. Right now I am swamped at work, only 8 days off since Jan. 1st, so it will be a while before I start building anything. Like Jon always says, this is where the Y part in diy comes in to play.

The drawings should give you a good idea of the brace layouts. The A braces are below the lower woofer and in between the two woofers. The B brace actually forms the bottom of the mid enclosure with the cut outs on the back side to open the rest of the enclosure to the woofers.

[Jim Holtz]

I have up dated the cut list and I have thrown together a very rough layout drawing. The cut list are for a PAIR of towers. Again there is a cutlist for both a 4x4 and a 4x8 sheet.

Due to the fact I have not built the cabinet yet these are estimates. Right now I am swamped at work, only 8 days off since Jan. 1st, so it will be a while before I start building anything. Like Jon always says, this is where the Y part in diy comes in to play.

The drawings should give you a good idea of the brace layouts. The A braces are below the lower woofer and in between the two woofers. The B brace actually forms the bottom of the mid enclosure with the cut outs on the back side to open the rest of the enclosure to the woofers.

Hi David,

I've been meaning to ask you what software you use to do the cabinet layouts? They are excellent!

Thanks!

Jim

[Rudy D]

The drawings should give you a good idea of the brace layouts. The A braces are below the lower woofer and in between the two woofers. The B brace actually forms the bottom of the mid enclosure with the cut outs on the back side to open the rest of the enclosure to the woofers.


Jim, David,
Thank you so much for all of your efforts. I really appreciate the time you put into this hobby. I believe I have all i need to complete. will send pic of process once I begin to build in earnest.

[Dotay]

Here are some pictures of how I am doing it.

How close are you to finishing this project? I'll be interested to hear your impressions on the difference between this design and the Natalie P that you've already built.

[Jim Holtz]

How close are you to finishing this project? I'll be interested to hear your impressions on the difference between this design and the Natalie P that you've already built.


(sigh) I'm the worlds slowest cabinet builder. :cry: I'm about 3 - 4 weeks away from completion.

I do have high expectations for the RS 3-ways. I know Dennis's designs very well. In emails he sent me during development, he heaped high praise on them in comparison to some very high end speakers he's familiar with so I think I can easily say, they'll be very, very nice.

That's not to say that the Natalie P's aren't a heck of a speaker too, because they are. However, 3-ways have always had a sound quality edge to my ears and are my 1st choice in a point source design.

YMMV

Jim

[kgveteran]

Once I get the tweeters output under control, these center(s) are going to sing.
I disconnected the tweeter to hear the 6" 150 mid blend with the 8" 225's and how smooth they are.It's pretty amazing the tweeter handles 1.8khz on up.

A sad note though....I was doing some testing with my PEQ and decided to build a filter to low pass the tweeter and take the edge off its output.Well I typed in 20khz on TruRta to get a starting point and run a test tone, thinking that would be my threshold place to work backward from.I couldn't hear a thing, I then typed in (working backwards)19k..18k....17k...16k...15k......14.5k (i finally started to hear the tone.....oh boy. I ended up with a two octave low pass at -9db around 14.5khz.Basically my hearing drops off pretty bad after 14.5khz :cry:

[ThomasW]

That's certainly not usual for any 25-30+yr old male, particularly if one has been in the military, worked any form of manufacturing or construction.

Wait until you're almost 60yr then test them again ..... :wink:

[kgveteran]

Maybe it was the 60 ton V12 M88 I used to drive while back in the 80's.Man, could that thing pull em' They called it "The Hook"

KG

Thomas,
Does that mean my future speaker designs won't need tweeters :rofl: .

[ThomasW]

I can still tell a good tweeter from a bad one. But my hearing craps out around 12kHz, and there's a -3dB dip at 3kHz in one ear.

Probably too many seasons welding up 3.3 million gallon fuel storage tanks when I was younger.....:wink:

[dawaro]

Jim - The program I use is a very, very basic drawing program called Smart Draw. If I remember right it was faily enexpensive also. I have access to Auto-Cad at work but so far I haven't had the access to the time to learn it. Maybe one day...

KG - As Thomas said don't feel bad about the ears. At 34 I have virtually nothing after 14K my self. On top of it do to an inner ear/sinus condition I have a ringing in one that constantly changes in amplitude. One of these days I am going to get it fixed, right after I learn Auto-Cad....

[Brian Bunge]

Yeah, I've got a full blown version of AutoCAD loaded onto my laptop and I have yet to take the time to learn it. I really should, as it would definitely be an advantage from a career standpoint. I keep seeing positions for techs and engineers requiring AutoCAD knowledge! :(

[kgveteran]

Sorry, I don't get out much anymore...

I'd revised this crossover some time ago, as while 1500 Hz shouldn't be any trouble for most examples of the RS28, it really didn't need to be crossed that low either. You can see the revised networks at this link:

http://www.geocities.com/cc00541/drRSWtmW_CC1800Hz.html

The tweeter now is crossed at 1800 Hz. Not much else really changed...

C

Dennis,
This is the design I built.It shows the polarity reversed on the RS28a and the RS150.I hope thats right.The positive from the source turns into the negative on the driver.

My question would be, when I get the L-pads, two wires get soldered together in the center terminal.Those two would usually be negative (one from the binding post and one from the driver ).Then the positive in from the XO board to the input on the L-Pad and positive out of the L-Pad to the drivers positive side......I think. :oops:

KG

[Jim Holtz]

Dennis,
This is the design I built.It shows the polarity reversed on the RS28a and the RS150.I hope thats right.The positive from the source turns into the negative on the driver.

My question would be, when I get the L-pads, two wires get soldered together in the center terminal.Those two would usually be negative (one from the binding post and one from the driver ).Then the positive in from the XO board to the input on the L-Pad and positive out of the L-Pad to the drivers positive side......I think. :oops:

KG
(edit to correct wrong information. This is now correct)

I'm not Dennis but I've miswired crossovers enough times I have it burned into my brain. Wire it exactly as the schmatic shows. The feed from the positive binding post does go to the negative terminal on the driver. The negative binding post to the positive terminal on the woofer.

Mids sound really hollow when they're wired wrong.

Jim

[ThomasW]

Oops we've got a problem... I forgot that the RS28 is a 4 ohm tweeter and no one sells 4 ohm adjustable L-pads anymore.....

So if you want an L-pad you'll have to make one from fixed value resistors

[kgveteran]

Oops we've got a problem... I forgot that the RS28 is a 4 ohm tweeter and no one sells 4 ohm adjustable L-pads anymore.....

So if you want an L-pad you'll have to make one from fixed value resistors

So the guy at PE was wrong when he propose I wire a stereo L-Pad in parallel :M .Hmm.

Jim,

I now have two interesting situations.On to the next.If you look at the schematic for the RS28 it shows the negitive turning positive? coming into the XO at the one end of the .25mH coil.You're saying that negitive wire continues to the neg terminal of the driver? Remember you can never over simplify when explaining to a troubled DIY'er :B

[BobEllis]

You should be OK if you put the lpad in series between the amp and the tweeter filter. Use two terminals on the L pad and it is now an expensive rheostat. If you haven't yet ordered it, go the fixed resistor route, though.

[Brian Walter]

I may be missing something, but if it is "stereo 8 ohm L-pad" then wiring both sections in parallel would give you a 4 ohm L-pad. I've never really looked a stereo L-pad, so I may be missing something. Look it over when you get it, I think it will work.

Brian

[BobEllis]

Doh! I think you've got it Brian. The PE guy didn't make a mistake.

[Jim Holtz]

Jim,

I now have two interesting situations.On to the next.If you look at the schematic for the RS28 it shows the negitive turning positive? coming into the XO at the one end of the .25mH coil.You're saying that negitive wire continues to the neg terminal of the driver? Remember you can never over simplify when explaining to a troubled DIY'er :B

Ok, now I'm having 2nd thoughts about my statement of wiring a reverse polarity crossover. I do so few of these I screw them up. The good news is, it's easy to tell when they're wired wrong.

Maybe one of the crossover guru's can jump in here and share their knowledge.

Jim

[kgveteran]

Doh! I think you've got it Brian. The PE guy didn't make a mistake.


Cool, seems that problem is settled.Thomas's advice was to use it for tests purpose,get the values and build a hardwire version.

[kgveteran]

Ok, now I'm having 2nd thoughts about my statement of wiring a reverse polarity crossover. I do so few of these I screw them up. The good news is, it's easy to tell when they're wired wrong.

Maybe one of the crossover guru's can jump in here and share their knowledge.

Jim


I'll post a link to the schematic and would like a little "input" from the XO guys.To review the question.Where does the L-pad fit into the hipass filter posted.Don't be afraid to "over" simplify.It can never get too basic.They won't show for a couple days so we can mill this over.And , did i wire it correct if the ground passes by the one leg of the coil and goes to the positive side of the tweeter :p:

http://www.geocities.com/cc00541/drRSWtmW_CC1800Hz.html

[Dennis H]

One thing that bothers me about these cabinet designs is the shallow (front to back) midrange enclosure. It's almost like an inwall -- not enough depth to damp the backwave. I'd be tempted to give up some woofer volume to give the mid room to breathe.

[Jim Holtz]

Jim,

I now have two interesting situations.On to the next.If you look at the schematic for the RS28 it shows the negitive turning positive? coming into the XO at the one end of the .25mH coil.You're saying that negitive wire continues to the neg terminal of the driver? Remember you can never over simplify when explaining to a troubled DIY'er :B


Ok, I spoke with Dennis Murphy to get the straight scoop and I was wrong. Follow the schematic exactly as it's shown. The positive binding post leg goes to the - terminal on the woofer and the negative binding post leg goes to the + terminal on the woofer. (sigh) I don't know why I struggle with that concept so much. I've also edited my previous post to be correct.

Sorry for the incorrect info in the previous post.

Jim

[cjd]

Dennis: it's probably one of those trade-offs, you know? I have found that multi-layer panel damping material makes a huuuge difference in this respect in particular, though.

C

[kgveteran]

Ok, I spoke with Dennis Murphy to get the straight scoop and I was wrong. Follow the schematic exactly as it's shown. The positive binding post leg goes to the - terminal on the woofer and the negative binding post leg goes to the + terminal on the woofer. (sigh) I don't know why I struggle with that concept so much. I've also edited my previous post to be correct.

Sorry for the incorrect info in the previous post.

Jim

Jim,
The problem is that Curt designed my XO not Dennis.If you look at the link I posted it shows the polarity swithed on the mid and tweeter.I Emailed Curt for some clairification.I think it is intended to be wired as is in the schematic.I'll just follow the directions when I get the L-Pads tomorrow.

KG

[Jim Holtz]

Jim,
The problem is that Curt designed my XO not Dennis.If you look at the link I posted it shows the polarity swithed on the mid and tweeter.I Emailed Curt for some clairification.I think it is intended to be wired as is in the schematic.I'll just follow the directions when I get the L-Pads tomorrow.

KG

I knew it was Curt's design. What I stated applies to all reverse polarity crossovers, not just the one Dennis created.

Jim

[wrz0170]

I knew it was Curt's design. What I stated applies to all reverse polarity crossovers, not just the one Dennis created.

Jim

wow. Glad I caught this before I started work on my center :E

Neophyte question: I looked up "L-pad" on PE. Looks like a volume adjustment. What exactly does it do and will I need one if I wire XO exactly as in the schematic?

[Jim Holtz]

wow. Glad I caught this before I started work on my center :E

Neophyte question: I looked up "L-pad" on PE. Looks like a volume adjustment. What exactly does it do and will I need one if I wire XO exactly as in the schematic?

There isn't a reason for a L Pad. The tweeter level is set during the voicing phase of the crossover design and padded appropriately. If the crossover was created from simulation only, most crossover designers have the experience to get it close without actually listening to it.

If the tweeter level doesn't match your tastes, there is a resistor in the tweeter crossover that can be varied a bit for taste and room conditions.

HTH

Jim

[kgveteran]

wow. Glad I caught this before I started work on my center :E

Neophyte question: I looked up "L-pad" on PE. Looks like a volume adjustment. What exactly does it do and will I need one if I wire XO exactly as in the schematic?

While running True Rta the graph looks fine.But, when listening I would like to pad it down a bit.This is a taste thing.

I built a filter using a PEQ and when i lowered the tweeter level I got SPL's well into the 95db range with little glare.I did listen to the mid and woofer without the tweeter and they blend well and sound fantastic.This is just a final phase tweak for me.

I will replace the L-Pad once i get it where i want it with fixed resistors.

[cjd]

When dealing with movies, tuning down the trebel is often (but not always!) a requirement because the audio tracks are laid down HOT in the trebel to work properly with an acoustically transparent screen and overcome the normal high frequency attenuation this introduces.

Have you tested with Lord of the Rings at all? They specifically remastered the sound on this disc so it is NOT hot in the trebel on this disc (as well as many/most of their others).

As such, it may in fact be worthwhile keeping this pad somewhere NOT permanent so you can tune it out on soundtracks where they've done this correction, and put it in on soundtracks where they have not.

C

[kgveteran]

Interesting.Most of my evaluations have been done with musi CD's and such.

I may keep it on the loop for tweaking purposes. Heck, once i get a handle on the tweeter I may go back to the vertical orientation...who knows :).

[Rudy D]

Just wanted to share my experience building the towers. Right now I have made all the cuts based on dawaro's cut sheet. I wish I could say it was as straight forward as measure twice cut once. It was more like measure several times, cut several times then recut from scratch. I'm having fun though building these towers. Just a couple of measurment changes I had to make. I'm not sure if it will help anyone else but here it go's. the mid-back enclosure measured (for me) 10.50" x 9.25'. Port hole (I'm building that version) is approximately 3.25" up from bottom and I measured 5.50 from side to middle( Where 4' hole cut will be made). The measured distance from Brace B to inside top enclosure is 10.50". this is the ported version so port brace I cut = 9.25 x 9.0. I have pic's but my file are greater than 100mb so I need to either figure out how to attach tumbnails and/or created a shared site so you can see my progress. Thought this might help someone that is comtemplating taking the plunge.

[Brian Bunge]

Rudy,

What exactly did you have issues with on the cut sheet? I haven't taken a look at it yet but will and see if I find any discrepancies.

EDIT: OK, I did look at the cut list as well as the diagram showing the cabinet layout. The one discrepancy I see is the back of the mid enclosure is said to be 11" x 9.25", but in the enclosure drawing it is shown as 11.5". I can't for the life of me figure out where you got 10.5".

Also, you said the port is 5.5" in from the side in the middle of the baffle width, but the baffle is only 10.75"W, which means that your port should be 5.375, or 5 3/8". Also, what port are you using? If you're using a 4" flared port your hole isn't going to be anywhere near big enough. IIRC, when I use them flush mounted the recess (or outer diameter of the port flare) is 7.25" and I use a 6.25" through hole. It fits very nicely like this.

Let me know if there were other problems with the diagram and cut list that I missed.

[Rudy D]

Brian
you are right the port measures 5.375 are noted. the inside height of the box is 40.50. If you use the great layout provided by dawaro you have to account for the .75 width of brace B. The measurment as posted is 29.25 +11.25=40.50 without taking into account the .75 width a Brace B. when you account for it, its 10.50 from brace B to top of internal cab. In terms of the port, yes taken into account flush mounting. Other then that i using that list and diagram and the bible, so to speak!

edit:
I am now going to increase the length of the mid-enclosure to reflect the 11.25" that dawaro originally posted.

[Brian Bunge]

OK, I got it now. So in other words, dawaro has both the diagram and the cut list wrong, assuming 40.5" for the internal height and the other brace placements are correct. So they both should be changed to reflect 10.5" for the length of the mid enclosure back.

[Rudy D]

I have up dated the cut list and I have thrown together a very rough layout drawing. The cut list are for a PAIR of towers. Again there is a cutlist for both a 4x4 and a 4x8 sheet.

Due to the fact I have not built the cabinet yet these are estimates. Right now I am swamped at work, only 8 days off since Jan. 1st, so it will be a while before I start building anything. Like Jon always says, this is where the Y part in diy comes in to play.

I think its good that we experiment and question so we can provide feedback.

[Brian Bunge]

Definitely!

In the meantime, here are some not so good pics of my center channel cabinet. Thanks again to Pete Mazz for painting the baffle and back for me!

[Rudy D]

just a quick question. giving the demensions of my mid enclosure, 10.50x9.25x5.625, which is appromately .75 less then dawaro dimension, are they still ok?
Edit;
the dimension should reflect the 11.25 posted in the diagram.

[kgveteran]

Definitely!

In the meantime, here are some not so good pics of my center channel cabinet. Thanks again to Pete Mazz for painting the baffle and back for me!

two comments about your cabinet.You opted not to use braces, or I just can't see them and the second:it looks like the midrange sub cabinet goes all the way to the back creating two separate enclosures for each 225.

[Brian Bunge]

That's basically 9L or .31ft^3, which is just fine. The difference in internal volume is negligible.

[kgveteran]

I installed the L-pads and they work fine. The knob is on the back and with just a few minutes to listen i think this is the thing I needed.It got a little late.I'll do some listening tonight and level them off with pink noise to ensure they match.


I had a recent email from XO designer Curt C. regarding some question I had and he had no problem with me sharing them with the forum.

I was wondering about the connection to the mid and tweeter.His comments were:
"Yes, the woofer to mid is approximately a 2nd order acoustic transfer function, which requires the mid to be connected reversed polarity due to the 180 degree phase shift. The mid to tweeter is actually an asymmetric 4th/5th but along with the flat baffle, provides a combination 360 degree phase shift.Hence the tweeter needs to be connected with the same polarity as the mid".

He also encouraged the final tweaking and to share my results with folks here who are thinking of pursuing this project.After some extensive listening of the original design and changing of positions both horizontal and vertical, the L-pad will give you the added adjustment that will add more versatility to this design.

KG

[michael stevene]

hello jim holtz,
are the dimensions for the sealed and ported tower cabinet the same? if not, where can i get the sealed dimensions?
thanks,
drmike

[Jim Holtz]

hello jim holtz,
are the dimensions for the sealed and ported tower cabinet the same? if not, where can i get the sealed dimensions?
thanks,
drmike

Michael,

The cut list along with the crossover post for the Seas H1212 on page 6 of this thread has everyting you're looking for. The external cabinet dimensions are 42"H x 10 3/4"W x 13 1/4" D. That's based on a 1 1/4" front baffle. I laminate 3/4" and 1/2" to reach the 1 1/4" thich front baffle. I also use a 3/4" roundover bit in my router to open up the inside of the front baffle around the driver mounting holes to reduce tunneling. I'm sure there are other ways to do this but this method works for me.

HTH

Jim

[Brian Bunge]

two comments about your cabinet.You opted not to use braces, or I just can't see them and the second:it looks like the midrange sub cabinet goes all the way to the back creating two separate enclosures for each 225.

Somehow I missed your post so I apologize for not responding sooner. Actually, there are 5 braces in the cabinet. There's a vertical brace running the width of the cabinet connecting the top, bottom and sides. Then there are the sides of the mid enclosure which connect to the back, top, bottom, and front of the vertical brace. Then there are the two braces that connect the back, top, bottom, and back of the vertical brace. These have large enough holes in them that I will be able to stick my hand in there and attach the mounting nuts for the 3 sets of binding posts that I will be using. The sides, top, bottom and braces are 3/4" thick, and the baffle and back are 1.5" thick.

The overall cabinet dimensions are 11.5"H x 28"W x 18.5"D.

[kgveteran]

Somehow I missed your post so I apologize for not responding sooner. Actually, there are 5 braces in the cabinet. There's a vertical brace running the width of the cabinet connecting the top, bottom and sides. Then there are the sides of the mid enclosure which connect to the back, top, bottom, and front of the vertical brace. Then there are the two braces that connect the back, top, bottom, and back of the vertical brace. These have large enough holes in them that I will be able to stick my hand in there and attach the mounting nuts for the 3 sets of binding posts that I will be using. The sides, top, bottom and braces are 3/4" thick, and the baffle and back are 1.5" thick.

The overall cabinet dimensions are 11.5"H x 28"W x 18.5"D.

If I would have looked at the other pic I would have seen the braces :roll: .

Cabinet looks great :T

[Rudy D]

Im in the thick of building the towers this link http://www.villagephotos.com/pubbrowse.asp?folder_id=1638657 willll allow you to see the pictures of my progress. tomorrow i will begin to put in the damping material. I haven't received the XO parts yets. More work on the boxes though. It will keep me busy for a while.

[wrz0170]

Im in the thick of building the towers this link http://www.villagephotos.com/pubbrowse.asp?folder_id=1638657 willll allow you to see the pictures of my progress. tomorrow i will begin to put in the damping material. I haven't received the XO parts yets. More work on the boxes though. It will keep me busy for a while.

Hey Rudy, looking pretty darn good there! :T

[Rudy D]

originally post by wrz0170
Hey Rudy, looking pretty darn good there!

Thanks! It is a lot of work and some time rework, but I'm enjoying the journey. Can someone tell me the depth of the recess for the drivers on the front baffle, and what size router bit?

[wrz0170]

Thanks! It is a lot of work and some time rework, but I'm enjoying the journey. Can someone tell me the depth of the recess for the drivers on the front baffle, and what size router bit?

Yep, know all about the "lot of work" and "rework". I have a sub under the belt and very soon to be finished NataliePs (tower version). I've learned quite a bit from those two projects Just need a clear coat and they will be done! Next up for me is the Center and Towers under this thread.

I make my recess just using a spiral up-cutting bit, plunge router and the Jasper circle jig. There are a couple ways of doing it, my way is a bit labor intensive in that I start the cut at the exact diameter of the driver. I then measure the thickness of the rim and I set that depth on my plunge router. I will then measure the distance from the rim, inward. I will make a series of cuts until I reach that inner measurement. About 4 or so passes, overlapping each cut to be sure I get it. I then punch through for the actual cutout. I usually take a scrap piece and make a practice cut to be sure of my measurements and make any adjustments from there. It's time consuming but it works for me. Some use a rabbeting bit to make a pass or two for the recess. I am just too lazy, cheap or both to go buy one :B

[Brian Bunge]

Per my digital caliper, the thickness of each driver mounting flange is as follows:

RS28A .135"
RS150 .161"
RS225 .202"

I usually dial it in as close as possible with test cuts and then take into account whether or not the baffle will be veneered or not.

[dawaro]

Since you have already made the cut outs for the drivers you are really down to two options for the flush cuts.

First you can make jigs the same size as the drivers and use a pattern bit to cut the recess. The easiest way to do it is to place the driver in the baffle and secure the jig around it, then remove the driver. This will help you get the alignment correct. Then just set the depth of the bit for the recess and follow the jig.

Scond option would be to use a rabbet bit. The problem here is most rabbet bits go up to a 1/2" cut and I think the flange on the drivers is 9/16" or 5/8".
You can check pricecutter.com or sommerfeldtools.com for rabbet bits that are large enough to make this cut.

[Brian Walter]

Rudy, there is one other option you can use as well. You could make a temporary plug to fill in the hole where the driver will go, and then use the Jasper jig or similar, to cut the recess for the driver. If you go this route, you will need to make three plugs, one for each size driver.

If you anticipate using the same drivers on severall different projects, it may make sense to build a template, as they are really easy to use and you can use it over and over. If you use a pattern bit, you will need to make sure your pattern is thick enough for the bearing to ride on the pattern and not cut into the baffle. Then with the router running you will have to plunge it down and route the recess. It would probably be easier to use a regular straight bit with a template guide bushing. The bushing runs along the edge of the template with the bit cutting inside of the template a little bit. The problem with using this technique, is that you need to make the diameter of the template bigger than the recess, to make up for the fact that the bit is cutting slightly inside of the template.

Brian Walter

[Rudy D]

thanks for the suggestions. I'm not sure which one I will use, but do appreciate the advise. stay tuned!

[Rudy D]

Originally posted by dawaro
Here are the files for the RS28A-S networks.
From talking to Dennis he feels that the sealed version is quite a bit smoother than the ported. Although he did note that it may have been due to the test box not being ridgid enough.

The final box size esternal dimensions are 10.75 w X 42 h X 21.5 d, Internal are 9.25 w X 40.5 h X 19.25 d.

The enclosure for the RS225's is 108 liter / 3.814 ft tuned to 27.29hz with a 4" port 9.2" long. Using one of the 4" PSP flared ports would be the best here. The result is an F3 of 28.05hz.

Attached are also cut list for a PAIR of towers. There is one cut list for a 4 X 8 sheet and one for a 4 X 4 sheet.

Make sure you check the math before you cut anything, I have been known to make mistakes in the area before

This question may have been answered in a previously. I didn't see it. however I have a couple of questions concerning the XO B.O.M and the use of certain components.
On the Schematics, I cant account for the following:
NET 1, R1011 = .500 Ohm. where is it on the BOM?
NET 2, R2051 = .300 Ohm. Where is it on the BOM?
NET 2, R2071 = .200 Ohm Where is it on the BOM?
Am I missing something?

[Paul H]

This question may have been answered in a previously. I didn't see it. however I have a couple of questions concerning the XO B.O.M and the use of certain components.
On the Schematics, I cant account for the following:
NET 1, R1011 = .500 Ohm. where is it on the BOM?
NET 2, R2051 = .300 Ohm. Where is it on the BOM?
NET 2, R2071 = .200 Ohm Where is it on the BOM?
Am I missing something?


I think if you check you'll find that those values are the inherent resistance of the inductors.

Paul

[Rudy D]

originally posted by Paul H
I think if you check you'll find that those values are the inherent resistance of the inductors.

Paul
Whew!, see this is when too much information is dangerous. Thanks I have included the link to my latest photos' and progress. I'm still waiting for my backorder from PE. I anticipate completing towers in 3-4 weeks. possibly sooner.

http://www.villagephotos.com/pubbrowse.asp?folder_id=1642586

[Brian Walter]

"Whew!, see this is when too much information is dangerous."

It really isn't too much information. That's how you know what gauge inductor to buy. You look up the inductors of the correct inductance and compare the DC resistance for the various gauges until you find the one closest to what is listed on the skematic. If this information wasn't given, you wouldn't know what was used in the model, of course if it was listed somewhere else you'd be ok.

Brian

[jkrueger]

Hey all
I'm a first time poster, just seeing if this works.....I have been following the TMWW portion of this thread with interest for a while. I have a question for anyone with the time and patience to answer. How would porting this project to the front change the final outcome? Or....To put it another way. Why is the TMWW ported to the rear? Thanks

[ThomasW]

I'll answer this only because you live on Vancouver Island, one of my favorite places on the planet ...:T

Putting the port on the rear is convenient and doesn't take up space on the front baffle. If you put it on the front, keep it away from the mid and tweeter.

Fair compensation for this highly technical answer would be a dozen large oysters fresh from the dock, or 1/2lb of dried cherries from the Overwaitea store.... :wink:

[Dan B]

The last time I put the port in the front you could kinda see inside.
Wires + foam = Ugly

[kgveteran]

As soon as PE can ship those RS225's I'll have three centers built......or the mains...or three maincenters....I'll post pics you guys let me know what you think :B

[kgveteran]

Well, all three are done.I had a chance to listen to them last night for a while.They look cool and I'll let you know how they measure up soon.

I just can't get enough of WOTW.First movie I threw in.

[ssabripo]

The resistors : 004-1 1ohm $1.25
004-4 4ohm $1.25
004-25 25ohm $1.25
004-10 10ohm $1.25

Caps are Dayton also, 027-430-12uF $3.55
027-436-20uF(2) $4.95ea.
027-432-15uF $4.10
027-410-1.0uF $1.15
027-428-10uF $3.15
027-447-100uf $19.51
027-434-18uF $4.65

Coils: 255-026 .25mH Janzen 20ga. aircore $1.94
255-250 1.0mH Janzten 18ga. aircore $4.41
255-230 0.5mH Janzten 18ga. aircore(2) $3.09
266-924 4.7mH Erse 16ga. ironcore $14.76

------------
$78.28


I used Dayton terminal plate 091-610 $9.75 (double binding post)
Binding posts 091-624(2) $19.90 (for both sets)


The midrange XO requires a 38uf cap.I used a 20uF and a18uF in parallel. It also reqired a resistor value of 35ohms, so I combined a 25ohm with a 10ohm in series.Watch the positioning of the coils.There is a great link to assist you should you choose to mount them like I did. Good luck :)


(2) RS225's $43.45 each (295-366)
RS150 $28.55 each (295-362)

RS28as-4 $49.45 each (275-135)


I just talked to PE trying to put the order in, and the guy suggested I use a 39uF cap (027-946) instead of using the 20uF and 18uF in parallel...he mentioned that you wont hear the difference, and that all these caps have tolerances so using the 20 + 18 in parallel will probably be more off than using a single 39uF.

any comments before I buy?

[ssabripo]

another question:

Curt had posted this regarding the RS150's XO:
http://www.geocities.com/cc00541/drobertsRSWtmW1800CCnet2.gif

notice that it has a 15uF cap for C2051 and a 9.25uF cap for C2031, where as on page one those caps are both 20uF :confused:

any ideas?

[ssabripo]

ok....I just went with Curt's post and not with what was posted on page 1 ...I also used a 39uF cap on the mid's XO, instead of the 38uF posted by Kg.

here is my BOM:

QTY PartNumber Product Price Ext. Price
1 004-1 DAYTON DNR-1.0 1 OHM 10W NON-INDUCTIVE RESISTOR $1.26 $1.26
1 004-10 DAYTON DNR-10 10 OHM 10W NON-INDUCTIVE RESISTOR $1.25 $1.25
1 004-4 DAYTON DNR-4.0 4 OHM 10W NON-INDUCTIVE RESISTOR $1.25 $1.25
1 027-410 DAYTON DMPC-1.0 1.0uF-250V POLYPROPYLENE CAPACITOR $1.15 $1.15
1 027-428 DAYTON DMPC-10 10uF-250V POLYPROPYLENE CAPACITOR $3.15 $3.15
1 027-430 DAYTON DMPC-12 12uF-250V POLYPROPYLENE CAPACITOR $3.55 $3.55
1 027-432 DAYTON DMPC-15 15uF-250V POLYPROPYLENE CAPACITOR $4.10 $4.10
1 027-436 DAYTON DMPC-20 20uF-250V POLYPROPYLENE CAPACITOR $4.95 $4.95
1 266-924 ERSE SUPER Q 4.7mH 16 GA 500W INDUCTOR $14.76 $14.76
1 004-25 DAYTON DNR-25 25 OHM NON-INDUCTIVE RESISTOR $1.25 $1.25
1 255-026 JANTZEN .25mH 20 GA AIR CORE INDUCTOR $1.94 $1.94
1 255-230 JANTZEN .50mH 18 GA AIR CORE INDUCTOR $3.09 $3.09
1 255-250 JANTZEN 1.00mH 18 GA AIR CORE INDUCTOR $4.41 $4.41
1 027-447 DAYTON DMPC-100 100uF-250V POLYPROPYLENE CAPACITOR $19.51 $19.51
1 295-362 DAYTON RS150S-8 6" REFERENCE SERIES SHIELDED WOOFER $28.55 $28.55
2 295-366 DAYTON RS225S-8 8" REFERENCE SERIES SHIELDED WOOFER $43.45 $86.90
1 091-610 DAYTON DBPP-SI DOUBLE BINDING POST PLATE SILVER ANODIZED $9.75 $9.75
1 275-135 DAYTON RS28AS-4 SHIELDED 1-1/8" ALUMINUM DOME TWEETER $49.45 $49.45
1 027-946 JANTZEN 39uF 400V CROSSCAP CAPACITOR $10.44 $10.44
2 091-624 DAYTON BPP-SN PREMIUM BINDING POST PAIR SATIN NICKEL $9.95 $19.90
1 UPS Ground $15.72 $15.72
Total: $286.33

[HMenke]

I'd like to kick off my DIY speaker career with a center channel, but I realize that the choice of the center channel can tend to constrain your later choices for L-R mains. So, I have some questions that may seem a little basic but here goes...

All things being equal, I like the idea of the Modula MTM or Natalie P mains. However, I am a little concerned about the same MTM layout arranged horizontally, even with Jon's special XO arrangement for that purpose.

It sounds like this WMTM center is the best route to avoid the inherent compromises of a horizontal MTM layout. So, given this particular combination of drivers, is it correct to say that the best timbre match for this WMTW center is the similar TMWW towers?

Also, why is the WMTM center a sealed design and the TMWW towers ported (given that the mains will likely be crossed over at 80 Hz to a sub). Is this intended to provide an option to listen to stereo music only without a sub?

Henry

[ThomasW]

Henry,

If you have the room and the budget, do a MT with flanking woofers (WMTW) for your center. They sound much better than the best optimized vertical MTM.

Since centers are primarily dialog, one doesn't need a ported bass section. And even built with real woofers, it best to run the center as 'small' and redirect any bass to your sub.

[Jim Holtz]

I'd like to kick off my DIY speaker career with a center channel, but I realize that the choice of the center channel can tend to constrain your later choices for L-R mains. So, I have some questions that may seem a little basic but here goes...

All things being equal, I like the idea of the Modula MTM or Natalie P mains. However, I am a little concerned about the same MTM layout arranged horizontally, even with Jon's special XO arrangement for that purpose.

It sounds like this WMTM center is the best route to avoid the inherent compromises of a horizontal MTM layout. So, given this particular combination of drivers, is it correct to say that the best timbre match for this WMTW center is the similar TMWW towers?

Also, why is the WMTM center a sealed design and the TMWW towers ported (given that the mains will likely be crossed over at 80 Hz to a sub). Is this intended to provide an option to listen to stereo music only without a sub?

Henry

Henry,

Thomas gave you excellent advice and I would mirror his thoughts about a center. I've had a W-T/M-W center for several years and it's the only way to go. I'm near completion on the sealed version of the WWMT RS 3-way. I'm spraying the cabinets tomorrow. I should have some listening impressions by the end of the weekend. I know Dennis Murphy well and there's no doubt in my mind that this is a steller design.

Sealed they should have excellent bass into the low 30's. Home theater requires that extra kick for explosions etc. where effects are more important than accuracy. I'd recommend a 12" - 15" sub to go along with the sealed RS 3-way for the best of both worlds.

My $.02 worth...

Jim

[HMenke]

Thomas and Jim: you have both confirmed that the W-T/M-W (Jim I like this nomenclature) is really the way to go for center channel duty. Thomas, in my room especially, your advice is well taken to run the center "small". I don't need more woofers exciting the problematic room modes!

I have the space I believe. See attached pic of my current front setup of Paradigm Mini-Mk3 and CC-300 (note: PS-1000 ported box sub is gone and RLp-15, 300L, 8" ported sonosub is now in left rear corner of room).

Budget: before I stumbled into this site, I was preparing buy an SVS PB12 Ultra for $1200, but happily spent only $800 on my DIY sonosub. I was also going to spend $550 for a Paradigm CC-470 and $680 for Studio 20's; since that ain't happening now, I am sitting on about $1600 budget for a new L-C-R array. Is that enough to work here without compromise?

Jim, you decided to complement your W-T/M-W with the sealed TMWW RS 3-ways. What factors led you to this decision? It sounds like a very nifty combination; the choice of sealed seems well-founded if a sub is involved, and yet you're not really giving up a lot in the way of bass response.

What are your thoughts on your TMWW RS 3-ways vs the TMWW towers suggested in this thread as a complement for this RS W-T/M-W center? The tweeters are the same but the midwoofers and woofers are not. Is the tweeter the most critical thing when matching front speakers?

[Jim Holtz]

Thomas and Jim: you have both confirmed that the W-T/M-W (Jim I like this nomenclature) is really the way to go for center channel duty. Thomas, in my room especially, your advice is well taken to run the center "small". I don't need more woofers exciting the problematic room modes!

I have the space I believe. See attached pic of my current front setup of Paradigm Mini-Mk3 and CC-300 (note: PS-1000 ported box sub is gone and RLp-15, 300L, 8" ported sonosub is now in left rear corner of room).

Budget: before I stumbled into this site, I was preparing buy an SVS PB12 Ultra for $1200, but happily spent only $800 on my DIY sonosub. I was also going to spend $550 for a Paradigm CC-470 and $680 for Studio 20's; since that ain't happening now, I am sitting on about $1600 budget for a new L-C-R array. Is that enough to work here without compromise?

Jim, you decided to complement your W-T/M-W with the sealed TMWW RS 3-ways. What factors led you to this decision? It sounds like a very nifty combination; the choice of sealed seems well-founded if a sub is involved, and yet you're not really giving up a lot in the way of bass response.

What are your thoughts on your TMWW RS 3-ways vs the TMWW towers suggested in this thread as a complement for this RS W-T/M-W center? The tweeters are the same but the midwoofers and woofers are not. Is the tweeter the most critical thing when matching front speakers?

Well, now you've done it. The truth is, I build these speakers for the fun of it. My reference system are the line arrays in my avatar. My wife calls it an addiction, I call it fun. What can I say. :oops: Here is a link to my main system. http://www.audiocircle.com/circles/modules.php?set_albumName=albur36&op=modload&name=gallery&file=index&include=view_album.php

Actually, I've built the Modula M/T's, Natalie P's, a custom monitor sized 3-way by Selah Audio and several others over the last several years. The RS 3-ways listed on page 6 in this thread are by a good friend of mine, Dennis Murphy. Dennis is the crossover wizard behind several very highly acclaimed commercial speakers from boutique manufacturers. I think the ones you're talking about are probably Chris's WWMTM design which I've not heard. I'm a big fan of the designs Dennis does so when he decided to do a RS 3-way, I had to build it. Plus I wanted to try out the Seas H1212 tweeter.

I'm also a fan of sealed designs for music. The bass just sounds right to me. I also find the smaller cabinets to be more placement and wife friendly. :D I would recommend the center crossover design by Dennis along with his RS 3-way for an excellent match. I'd also build the Seas H1212 version rather than the RS28 version. It won't affect matching in the slightest and I like the top end of the H1212 better than the RS28. YMMV

Budget wise, you're going to have a fair amount of money left over if you can build your own cabinets. I have 2 different BOM's listed for the RS 3-way. They're $460 - $500 depending on resistors, caps etc. I'm thinking the center is about $275 for drivers and crossover parts.

BTW, If you build this center, run it full range. I looked at your room and it should be fine. The bass will be very, very clean and tight.

HTH

Jim

[ThomasW]

I am sitting on about $1600 budget for a new L-C-R array. Is that enough to work here without compromise?
Sure......

But I'm a big fan of MTM's for HT mains (like Jon's Modual MTM). I like the dispersion characteristics, lower complexity, lower cost, and there's more radiating area for the midrange compared to a single smaller midrange driver used in the MTWW. MTM's have less bass than a 3 way with woofers, but you've got a big sub, so you don't need big bass from the mains.

[HMenke]

Jim your line arrays in your avatar are very impressive. I went to visit your system link but the images aren't loading. Given enough time I may end up like you...my wife already thinks I'm off the deep end with this stuff.

Now you've got me pondering tweeters and crossovers too. I'll need some time to sort that out...

A sealed center is preferable for my application because as you can see I have the center up against the front wall. It works fine with the current CC-300 because it is an MTM ported on the front. Regarding running the center full-range vs small, I'll probably run small but might experiment. I have tried running large with the CC-300 and it bloated the mid-bass region when added to the sub's output. That said, it is surprising how much bass some soundtracks send to the center for dynamic impact, for example the opening scene in T2 where the metal Terminator stomps on a skull at the destroyed playground.

Thomas you basically gave me what I was looking for: the confirmation that MTM mains flanking a W-T/M-W is a solid combo. I am coming off small 2-way mains that, except for being output limited, work pretty well - so MTW makes sense as a logical step up. That MTMs would be less expensive and less complicated to build is a nice bonus! Due to the proximity of the walls and corners, would it be better to build them sealed too? I can probably get 18" from the back wall and 12" from the sides.

I will probably build my own cabinets. I have an assortment of solid walnut, oak, and cherry available to me. The PE cabinets are tempting because they are functional and economical, but there's something about them aesthetically that doesn't work for me. Do you guys bother with grilles or just dispense with them?

If I do everything 'right' with these builds, what are the chances I won't like the sound? My only reservation about building these is the lack of opportunity to know if they will be at all to my taste. That's why I decided to start with a center: to limit the downside if that happens. I tend to prefer a neutral sound that is neither bright nor overly warm, without voice sibilance and without male voice boxiness/chestiness. I can only hear up to 15kHz so what the tweeter does beyond that is irrelevant to me.

[ssabripo]

Thomas, Jon, Jim, KG...anyone!

is it me, or does the cabinet pics from KG's setup look like the depth is approximately the same as the height (12.5")?

the reason I'm asking is that I'm about to start cutting wood, but although the diagram on post 1 shows the depth dim. to be 12", there is a big disclaimer saying the depth should be 16", not 12".........BUT, looking at the pics, sure looks like it ought to be 12" or so (matching the height).

any ideas?

[kgveteran]

The original posted depth is wrong,the designed depth is 16".I made all of mine with the 12" depth due to my needs.I cross over at 100hz.I have no need for the extra extention in response.Also there is no need to adjust the XO."It's a bass thing"

Once I get the L-pad centered where I want it, I'll post a valued resistor to add in serie to help pad down the tweeter.At this point the L-pad is wired with the shunt connected to ground.I'll experiment to see if there is a big difference between that connection being lifted.

In my hast I connected one of the 8" woofers out of phase.Boy did that sound like crap.After running some sweeps with Truerta I found the problem.At close range they are all looking the same.I wish it were that easy out in the room.I always endup looking at the final sweep at 1/3rd or 1/6th oct.

I'm sure the center weighs at least 75lbs with the smaller depth,watch your back picking up these rocks.

[ssabripo]

Thanks Kg....that's what I thought! Cool....I will keep you guys posted.

[kgveteran]

I hope someone trys Dennis's design and Jon's.I'd be willing to go and take a listen.Keep it close to NY though :B .

[ThomasW]

Henry,

I've never put a grill on any speaker I've ever make. I like seeing the drivers, and there aren't any little fingers in my house around to poke at things.

[HMenke]

The little fingers in my house are fully trained in the Wrath of Dad, so I will probably leave off the grilles.

In this center, can you use the SEAS 27TDFC (H1189) to better match up to Jon's Modula MTM?

[Brian Bunge]

I'm sure the 27TDFC could be incorporated into the design, but someone would have to modify the crossover.

Also, above you mention that you are going to build your own cabinets and that you have solid walnut, oak and cherry available to you. I just wanted to make sure that you understood that you cannot use solid wood to build a speaker cabinet. Well, you can, but you shouldn't. Solid wood does not have uniform density and can expand and contract far too much to be used for such an application.

[kgveteran]

Well after some monkeying around, this is what I came up with.I couldn't get the new mains to sound like my old Paradigm Mini MK3's.The problem with the mini's is they would breakup above 80db with movies or music.They sounded great ,but lacked headroom.

I hooked them up and ran a sweep to see what they( the Mini's ) were doing that the new mains were not.Seems that the Mini's had a broad dip centered at 2khz.So I saved that in memeory #1.The dip was about 4-5db and was very wide.
I ran a sweep on the new center (the actual center) and it had a peak centered at 2khz.I used one band on my PEQ and reduced it, very broad like the Mini, and boy if it didn't sound like the damn Mini.
I now have a center that sounds like my old favorite with tons of headroom.

Does this seem an odd way of doing things? I never thought that I could model a monitor and get mine to do the same.

Tomorrow I'll run some movies to see if they hold up under presure.Too late for that now.

By the way I'm listening to the SACD of Diana Krall, "The look of love". Things are looking up.

Edit:

After watching "Zathura" and "Narnia" I'm able to get this rig up to reference level without a hitch.I measured 105db total system and it was pretty unbelievable.I have increased the tweeter output and I have also increased the "BBC" dip a bit.The left and right aren't as sensitive to frequency response as the center.Once i figure how to post TrueRta screen shots i'll get them out to you guys.

KG

[HMenke]

I'm sure the 27TDFC could be incorporated into the design, but someone would have to modify the crossover.

Also, above you mention that you are going to build your own cabinets and that you have solid walnut, oak and cherry available to you. I just wanted to make sure that you understood that you cannot use solid wood to build a speaker cabinet. Well, you can, but you shouldn't. Solid wood does not have uniform density and can expand and contract far too much to be used for such an application.Re: 27TDFC I was afraid that would be the case. My current speakers have textile dome tweeters and I am not sure if I will like the metal dome type.

I did not know that solid wood could not be used for speakers. Thanks for pointing this out before I got into it! Now that I think about it, I bookmarked your enclosure as an example of being very nicely done. Can you tell me a little about how you went about constructing them?

[cjd]

kg: sounds like you're one of those that prefers a "BBC" dip. Though 4-5dB is excessive (or seems so to me, but then I prefer no BBC dip), it is not unusual in a commercial speaker. The other way of thinking about it is boosted bass and tweet. Very common profile to see on graphic EQ's.

Are you able to share the graphs you're seeing? You might find that no more than ~2dB is a good target, but your ears will take getting used to it, If/when they do, the old profile will seem to be lacking detail and clarity. ;)

Regardless, in the end, it is about finding something you like.

C

[Brian Bunge]

My cabinets are just 3/4" MDF with bracing and a 1.5" front and back. The front and back sit in a rabbet that's 1/8" shallower than the thickness of the inner piece, so that it leaves a 1/8" "relief" between the front and back and the rest of the cabinet. I veneered the cabinet in figured cherry veneer and had the front and back painted gloss black.

[kgveteran]

kg: sounds like you're one of those that prefers a "BBC" dip. Though 4-5dB is excessive (or seems so to me, but then I prefer no BBC dip), it is not unusual in a commercial speaker. The other way of thinking about it is boosted bass and tweet. Very common profile to see on graphic EQ's.

Are you able to share the graphs you're seeing? You might find that no more than ~2dB is a good target, but your ears will take getting used to it, If/when they do, the old profile will seem to be lacking detail and clarity. ;)

Regardless, in the end, it is about finding something you like.

C

It really is a "presence" adjustment.I kept trying to move the speakers back against the front wall because there was too much midrange sound and it had a "in your face" sound.I'll play around with this a bit until I get it were I like it.Seems I have a British ear :)

[cjd]

With orchestral works, you'll lose the violin section with that much dip. ;)

A lot of it is a function of what kind of music you listen to. Many people that do a lot of female vocals would be surprised to hear a live un-amplified singer and discover they've been smoothing the sound all these years. The specific recordings likely play a role too.

There is a lot of critical information there, which is why I think 2, maybe 3dB is good but more starts to lose fidelity a bit much.

Your ears really so get used to a sound, and will gravitate to the familiar even if it's not ideal. This is not limited to your ears - if you were to lose your glasses, you would likely gravitate to similar frames even if you were trying not to. (Been down that specific road.)

Might be interesting to dial out ~1/2 dB of that dip every week or two, see if you hit a point that is not too forward that is different from what you are used to.

C

[HMenke]

My cabinets are just 3/4" MDF with bracing and a 1.5" front and back. The front and back sit in a rabbet that's 1/8" shallower than the thickness of the inner piece, so that it leaves a 1/8" "relief" between the front and back and the rest of the cabinet. I veneered the cabinet in figured cherry veneer and had the front and back painted gloss black.

Thanks for the details. It looks very attractive. Nice job on the veneer and color choice for the front and back. :T

[HMenke]

Brian, do you see any issues with these construction details? I have not detailed your 1/8" rabbeted reveal, just a flush front baffle for now. I also opted for a fully recessed rear baffle.

In particular I wondered about how much to relieve the back sides of the drivers. Right now I have 1/2" roundover shown. I have shown multiple side views of the front baffle for clarity. I am also wondering about the placement of the midwoofer/tweeter braces (see Front Baffle view).

I squeezed the tweeter and midwoofer as close as possible but still leaving 1/8" material between the flush mount counterbores. How deep should the counterbores be for each driver type?

- Thanks

Henry

http://home.insightbb.com/~henry.menke/TOP_VIEW_CC.jpg


http://home.insightbb.com/~henry.menke/FRONT_SIDE_VIEWS_CC.jpg


http://home.insightbb.com/~henry.menke/FRONT_BAFFLE_CC.jpg

[Brian Bunge]

From what I can tell you have everything right. I kept the 225's spaced the same distance apart as the original design but just added 2" to the overall cabinet width. Also, I'm not totally sure you can actually get the mid/tweet CTC spacing at exactly 5" due to the diameter of the RS150. I want to say mine are maybe 5 1/8" CTC but that's been months ago and it's kind of hard to measure accurately when there's no center point for each driver on the baffle anymore. I can tell you that there's a tiny sliver of MDF separating the two of them. Either way, I'd draw out the driver layout on your baffle and make sure everything looks good before you go cutting holes.

I had to double check mine, but it looks like I used a 1/2" roundover behind the 225's and 150 as well. The braces that create the mid/tweeter enclosure look good also. I think that you've got everything right.

[HMenke]

Alright, cool, thank you. I won't be cutting until I get the drivers in hand, check their dimensions precisely, and add them to the baffle drawing.

On the mid/tweet braces it's hard to see, but the woofer rear roundovers go under the outsides of the braces. Since I'd be doing all the driver roundovers before assembly, I guess that means I'll need to go back and relieve the braces by hand after assembly.

Are you using wood screws to hold the drivers? What are your thoughts on crossover locations? I was thinking they'd go in the bottom of the three rear chambers.

I'm still conflicted about tweeter selection. What I want is a SEAS 27TDFC fabric dome to match Jon's Modula MTM with the same type, but there's no crossover for this project. So I guess the most straightforward path is to go RS28A here and then also with the Modula MTM. I'm just worried that I'll be unlucky enough to get one or more of the "marginal" units that have QC issues, plus I'm just not sure about the sound of a metal dome.

[kgveteran]

Hmenke,
Did I miss it or have you not picked which XO you are going to use ?

cjd,
I'll give it a try.On some CD's I do get a bit of a shallow sound stage.It is a relief from the "In your face".I'll add a bit each few days and keep listening.Thanx.


KG

[HMenke]

Hmenke, Did I miss it or have you not picked which XO you are going to use ?No, you didn't miss it. I haven't decided on an XO.

I am leaning toward Dennis Murphy's over Curt's. My reasoning:
a) He is crossing over the tweeter higher. After all, this is a 3-way, so why not take advantage of the fact that there is a midrange? I don't really understand the reasoning behind trying to cross the tweeter as low as possible.
b) He is rolling off the midrange faster on the bottom. Again, it's a 3-way, so let the woofers do their thing and let the midrange deliver dialog.
c) He's tweaked it with listening tests.

I am also leaning toward Dennis Murphy's over Jon's. My reasoning:
a) Jon's design is more complicated and therefore expensive.
b) I'm not sure if there are sonic advantages to such steep filters to offset the costs.
c) I may be off base here, but I believe the phase shifts with steeper filters are more severe than with gentler slopes.
d) Dennis has tweaked with listening tests.

As I said above, I'm also hesitating to go with the RS28A due to the metal dome. Your posts about experimenting with tweeter L-pads due to an "in your face" sound have spooked me, because I am - like you - coming off the early Paradigm Mini-Mk3 L-R with the fabric tweeters and the matching CC-300 center with the same tweeter. However we don't have a fabric-domed tweeter crossover for this speaker design.

Henry

[Brian Bunge]

There won't be any reason to "relieve" the braces. Based on your pictures (and my cabinet sitting in front of me) only the outer frame extends over where the braces are. There isn't enough of the brace sticking into the rounded part of the back side of the baffle to worry about, IMHO.

I believe the in your face sound has absolutely nothing to do with the fact that the RS28A is a metal dome. It has much more to do with having a flat frequency response through the vocal range of the audio spectrum. Also, I haven't heard of any issues with the RS28A's in quite some time and mine seem to be just fine, so I think you are worrying about nothing at this point.

[Dennis H]

What Brian and Chris said. When you're used to the sound of bad speakers, you tend to be disappointed in the sound of good speakers because they don't sound like what you're used to. Give yourself time to live with the good speakers for a while and get used to them and you'll wonder what you ever liked about the bad ones.

[kgveteran]

"As I said above, I'm also hesitating to go with the RS28A due to the metal dome. Your posts about experimenting with tweeter L-pads due to an "in your face" sound have spooked me, because I am - like you - coming off the early Paradigm Mini-Mk3 L-R with the fabric tweeters and the matching CC-300 center with the same tweeter. However we don't have a fabric-domed tweeter crossover for this speaker design." QUOTE


The Mini MK3's have a great sound at low volumes.They run into trouble when increased SPL require the woofer to work too hard and that throws off the midrange, even when XO at 100hz.

Last night I ran a sweep of the Mini and found the "BBC" curve in the response.A dip of about 4db centered at 2khz.I duplicated that with my RS center and mains, along with some padding down of the tweeter with an L-pad and I'm where I started.Let me explain....

I now have very clear highs, the mids are reduced enough to get me closer to the "Mini sound" I liked before.The plus is I was listening at 85db without a hint of breakup or stress like before.The tweeter is very open.The mid sounded fine with out the "In your face" sound.Keep in mind I have a smallish room and the mains and center are only 8' from my listening position.I never wanted more than 85db with the ability to do the peaks at 95db without strain.I believe I have that now.Through some emails with Curt, he wanted me to share this with you guys and it may or may not encourage him to tweak his XO for the future.I am much closer now than a week ago to my goal.

One thing I have learned in my travels with HT is that a system that can deliver 85-95db from 8hz to 20khz without strain leaves me wanting no more.A truly balance system with a frequency response like that suites me fine and meets my expectations.For 400.00 each they are a steal.

My son will be getting Narnia tomorrow from "you know who" and i'll listen very carefully to what will be done next.Hopfully nothing , but I doubt it...there's always something to do next......

[kgveteran]

What Brian and Chris said. When you're used to the sound of bad speakers, you tend to be disappointed in the sound of good speakers because they don't sound like what you're used to. Give yourself time to live with the good speakers for a while and get used to them and you'll wonder what you ever liked about the bad ones.

I don't doubt that statement at all.I've only had all three built for about a week now.I'm trying to get back to where I was before, then I can move out and onward.Last night really did it with the discovery of the curve in my last monitors.

[HMenke]

kg, I have never heard of the "BBC" dip; I found this interesting commentary (from http://www.nutshellhifi.com/Arieltxt2.html):

The Ariel now sounded sweet, relaxed, and natural. The 2-meter on-axis measurement (shown above with no response smoothing) followed the intended 2dB slope from 100Hz to 10kHz with a very mild recession around the 3.8kHz crossover region. This is the classic "BBC dip", and much preferable to a "forward" emphasis in the upper midrange. Since ear is approaching its greatest sensitivity in the 2-5kHz region, even very small peaks create an unpleasant and unnatural sibilance. By contrast, a small dip in this region results in a slightly more distant perspective, and a more relaxed sound.

The "BBC dip" is in the most sensitive region of hearing (refer to a Fletcher-Munson curve) and very small adjustments in the value of the tweeter capacitor can "trim" the perspective of the soundstage. If the sound is too "polite" and distant for your personal taste, increase C1 to 5.6 uF; if it is too forward and "in your face", drop back to 5.0 uF.I must be one of those people who prefer the BBC dip - I just never knew it. I selected my speakers based on how they sounded. I had no idea the Paradigm Mini-Mk3s behave this way and that this could be the reason I preferred them.

[HMenke]

This is interesting...in digging around, I found that the XO frequency Jon used for the SEAS 27TDFC in his RS180 MT looks like it matches up pretty well with Curt's XO frequency for the RS28A in his WTMW center XO.

Perhaps, starting with Curt's overall WTMW XO, Jon's tweeter XO and the 27TDFC could be substituted for Curt's tweeter XO and the RS28A? If yes, then I would be all set to later use Jon's Modula MTM-1 with the 27TDFC as well.

http://home.insightbb.com/~henry.menke/Jon_Marsh_MT_SEAS_XO_FR.jpg

http://home.insightbb.com/~henry.menke/Curt_Campbell_WTMW_XO_FR.jpg

A nice thing about Jon's 27TDFC XO for his RS180 MT is that it is pretty simple (and I gather that is rather uncharacteristic for most of his designs). :D

[Jim Holtz]

I finally completed Dennis Murphy’s Seas/RS 3-way design yesterday and spent several hours listening. I’m familiar with the RS drivers after building Jon Marsh’s Modula M/T and Natalie P. designs so my expectations were indeed high. These speakers way exceeded my expectations. :D

Superb dynamics, excellent detail and awesome bass are the 1st things that come to mind. I like neutral speakers and these are extremely natural sounding with loads of “the performers are here in the room” imaging.

The Seas H1212 is an amazingly good tweeter. I like the sound of the RS28 but felt it was a bit dead sounding on the top end. The H1212 in comparison has the same full bodied sound in the lower treble but is very extended and airy. It is really, really a nice tweeter and a bargain for the price.

I’m also just as impressed with the bass. After listening to several bass heavy test CD’s, I concluded ported alignments just aren’t necessary. It has very deep, clean and accurate bass, IMHO. Pipe organs might not be reproduced to their fullest, but you won’t miss much else. The bass is just exceptional and one of the best speakers I’ve heard in this regard.

The clarity of the mids is excellent as I expected. The details that are masked by lesser speakers are easily heard and blend into the overall sound as they should. The mids are extremely accurate, smooth and detailed.

This design is one of those speakers that does everything extremely well, and many aspects so well, that you have to wonder how much better it can get. They are more than a taste of high end sound and would embarrass many mega buck speakers I’ve heard. It’s hard to believe that the cost of drivers and crossover parts is less than $500 for the quality of sound they produce.

Highly recommended and a definite two thumbs up! :T :T

(Edit) Photos added 4-22-2006. Speakers complete without grills.


Jim

[Jed]

Jim,

Maybe you can convince Dennis to do an exclusive 882 re-mix? Of course, maybe the RS150s are better mids, I don't know. They both sure measure well. What slope crossover is Dennis using? Any pics of your new speakers?

Jed

[Jim Holtz]

Jim,

Maybe you can convince Dennis to do an exclusive 882 re-mix? Of course, maybe the RS150s are better mids, I don't know. They both sure measure well. What slope crossover is Dennis using? Any pics of your new speakers?

Jed

Hi Jed,

I doubt that Dennis has time right now based on the number of projects he's currently working on. I plan on doing a project with the 882's late Fall/early winter but I'll use a different tweeter. The ability of the 882 to cross higher opens the door for 3/4" domes and some ribbons. I have a pair of Fountek NeoCD3.0's that will be used. Based on the bass the RS 3-ways are putting out, I'll use them for them again for sure.

Dennis used all 2nd order slopes in the RS 3-ways. In spite of everyone saying it can't be done sucessfully with the RS drivvers, they are ultra smooth with not a hint of hardness anywhere. Sweet!

I'll have them at the DIY events in the Midwest this Fall if possible so others can hear and comment. No pictures yet. I don't have the grills done yet. I'll post pictures when they're totally done.

Jim

[HMenke]

Henry,

If you have the room and the budget, do a MT with flanking woofers (WMTW) for your center. They sound much better than the best optimized vertical MTM.Thomas, when you said "They sound much better than the best optimized vertical MTM.", did you mean that they sound better than a vertical MTM optimized for horizontal placement, or better than a vertical MTM placed in the center vertically?

Henry

[Brian Bunge]

I'm sure he meant "best optimized horizontal MTM".

[gengle]

Hi,
I want to find someone locally to make the WMTW Enclosure for me.

I don't understand the crossbracing inside. Is the MT completely enclosed and isolated inside the box in the middle?

Is the inside box centered in the enclosure?

How do the W(s) fit with the crossbracing?

Seems I would need a side view or more detailed info to hand over to the person constructing. Are there any more details available?

I did see where the depth was changed to 16"

3/4" MDF?

Is it designed where the front is removable for access?

Thanks

http://home.houston.rr.com/roberts17207/Dayton%20RS%20Center%20Layout.jpg

[kgveteran]

The midrange is isolated from the woofers, who share the rest of the space together.

Yes, the subenclosure is centered.

The braces need to be knotched out to fit the magnet structure.I had my cabinet guy make the notch the width of the woofer opening.I also had him drill 3" holes in the back of the brace towards the back, so air wasn't isolated in a corner.

The 16" depth will give better bass extention.I cross mine over at 100hz, thus I kept the 12" depth.

3/4" MDF if fine.The baffle is double thickness.

A cabinet guy can make the front removable if you wanted.I'm not sure if you want that though.

Make sure you have the drivers so he ( your cabinet guy ) can see and double check the rabbits so the speakers fit flush and the openings are right.

My guy did each one for 125.00 , find a smaller shop.The big shops in my area would use the CNC machines and they wanted 200-250.00 each.Shop around for the best price.

KG

[HMenke]

Seems I would need a side view or more detailed info to hand over to the person constructing. Are there any more details available?I have not built the cabinet yet, but I worked on a CAD file of the cabinet. Brian Bunge, who has built one, confirmed it. This design has some differences to the drawing at the beginning of the thread. It is larger with more internal bracing. Check this post:

http://www.htguide.com/forum/showpost.php4?p=248202&postcount=404

If you can use CAD files, send me a PM and I'll email them to you.

Henry

[Jim Holtz]

I updated my post about completing Dennis Murphy's RS 3-way with photos if anyone is interested. No grills yet but they are in progress when I can take the time to finish them.

RS 3-way photos (http://www.htguide.com/forum/showpost.php4?p=248378&postcount=415)


Jim

[kgveteran]

great job.....and how do they sound ?

[knifeinthesink]

where are the plans for the Dennis murphy mains?

[ssabripo]

I updated my post about completing Dennis Murphy's RS 3-way with photos if anyone is interested. No grills yet but they are in progress when I can take the time to finish them.

RS 3-way photos (http://www.htguide.com/forum/showpost.php4?p=248378&postcount=415)


Jim


looking good Jim.. :T

Did you put veneer on that, or did you use real oak wood?

[dawaro]

where are the plans for the Dennis murphy mains?
Post #258 I think...

[dawaro]

great job.....and how do they sound ?
From Jim's earlier post...
"The Seas H1212 is an amazingly good tweeter. I like the sound of the RS28 but felt it was a bit dead sounding on the top end. The H1212 in comparison has the same full bodied sound in the lower treble but is very extended and airy. It is really, really a nice tweeter and a bargain for the price.

I’m also just as impressed with the bass. After listening to several bass heavy test CD’s, I concluded ported alignments just aren’t necessary. It has very deep, clean and accurate bass, IMHO. Pipe organs might not be reproduced to their fullest, but you won’t miss much else. The bass is just exceptional and one of the best speakers I’ve heard in this regard.

The clarity of the mids is excellent as I expected. The details that are masked by lesser speakers are easily heard and blend into the overall sound as they should. The mids are extremely accurate, smooth and detailed.

This design is one of those speakers that does everything extremely well, and many aspects so well, that you have to wonder how much better it can get. They are more than a taste of high end sound and would embarrass many mega buck speakers I’ve heard. It’s hard to believe that the cost of drivers and crossover parts is less than $500 for the quality of sound they produce.

Highly recommended and a definite two thumbs up!"

[Brian Walter]

They look really good Jim. I can hardly wait to get mine done. It'll be a while though, I just started my cabinets today. They're going to have curved sides, similar to some of the B&W and Kef speakers. It'll take a little longer than a retangular box, but I think the extra effort will be worth while. I doubt it will have much if any affect on the sound. By the time I'm done I may wish I'd kept it simpler, but what the heck, this is supposed to be fun right?

Brian Walter

[michael stevene]

what is the final depth? how many braces? link to cut out diagram?
thanks,
drmike

[kgveteran]

what is the final depth? how many braces? link to cut out diagram?
thanks,
drmike

As designed (if we are talking about the center ) 16" . I made mine before the mistake was found.it made little difference due to the 100hz XO I use.I prefer the 12" design.

[Dougie085]

Is it really that much worse going the economy way? I mean its like 50 bucks difference which isnt huge, I'm just curious if its that much better with the more expensive parts? And also im curious if anyone on here lives in the Pittsburgh area that has the tools to build the enclosures for the towers? If so pm me please :) and if necissary I could pay for the help and what not? One way or another anyways lol beer maybe? :B

[Jim Holtz]

looking good Jim.. :T

Did you put veneer on that, or did you use real oak wood?

I used Veneer and stained it in golden oak. Then sprayed them with Crystalac. Awesome product, BTW. It is ultra clear and dries rock hard.

Jim

[Jim Holtz]

where are the plans for the Dennis murphy mains?


Here are links to the posts on page 6 of this thread that contain everything you need to build them.

Jim

Sealed Seas version:

http://www.htguide.com/forum/showpost.php4?p=235850&postcount=258

http://www.htguide.com/forum/showpost.php4?p=235961&postcount=261

Ported RS28 version:

http://www.htguide.com/forum/showpost.php4?p=235867&postcount=259

[Jim Holtz]

what is the final depth? how many braces? link to cut out diagram?
thanks,
drmike

The dimensions are 42" H x 10 3/4" W x 13 1/4" D (with a 1 1/4" front baffle). The cut list in the original post will give you nearly all of the dimensions neded. Here are pictures of the rough construction that might help.

Jim

[Jim Holtz]

They look really good Jim. I can hardly wait to get mine done. It'll be a while though, I just started my cabinets today. They're going to have curved sides, similar to some of the B&W and Kef speakers. It'll take a little longer than a rectangular box, but I think the extra effort will be worth while. I doubt it will have much if any affect on the sound. By the time I'm done I may wish I'd kept it simpler, but what the heck, this is supposed to be fun right?

Brian Walter

Hi Brian,

I think you'll like them a lot. Does this mean we're going to have a couple RS 3-ways at this falls DIY events? :D

Your design sounds like it will be very pretty. I'm not that accomplished of wood worker. Plus they have to blend into the decor of our living room which limits the look to a degree. I'm looking forward to seeing your final product this fall.

Jim

[michael stevene]

hey jim,
could you give the position of the braces?
thanks,
michael stevener

[Jim Holtz]

hey jim,
could you give the position of the braces?
thanks,
michael stevener

Michael,

I assembled the basic cabinet and cut the front baffle. I then laid the front baffle on the empty cabinet to determine where I wanted the braces. I didn't write it down and it's been several weeks ago so it's slipped my mind.Not hard when you are more "mature" like me. :W

Sorry, I can't be of more help.

Jim

[Joe L.]

Do you see any issues with these construction details?
- Thanks

Henry

Henry,

I'm in the process of finalizing my own plans for this project. Like you, the original dimensions don't work well in my theater, so I'm going to make the enclosure a bit wider, slightly less deep, and of slightly less height.

The original plans (after correcting the depth) show overall dimensions of
12.5 H x 26.0 W x 16.0 D

After figuring for the enclosure wall thickness I get the following for the internal dimensions: 11 H x 24.5 W x 13.75 D (double thickness front baffle, single 3/4 inch MDF otherwise)

This results in an internal volume of 3705.6 cubic inches or 2.144 cubic feet.

Looking at your very nicely done plans I see overall dimensions of
11.5 H x 26.5 H x 18.5 D

After figuring for the enclosure wall thickness I get the following for the internal dimensions: 10 H x 25.0 W x 15.5 D (double thickness front and rear baffle, single 3/4 inch MDF otherwise)

Your modified plan results in an internal volume of 3875 cubic inches or 2.242 cubic feet.

It appears as if you have increased the internal volume by 170 cubic inches. Is this to accommodate more bracing? Yeah, I know it won't make too much difference, but I'm trying to keep close to the original size. From what I can see you could reduce your enclosure depth by .5 inches, or your enclosure width by an inch and end up with a size much closer to the original internal volume.

My plan is to make the enclosure 12 H x 27.5 W x 16 D. Internally, it would then be 10.5 H x 26 W x 13.75 D. It would end up as 3753 cubic inches volume, only slightly more than the original plans (I plan to use a double front baffle and single rear as on the original drawing.) If I add an extra brace or two and I should end up almost exactly the same internal volume as the original design

I've started by cutting some of the initial pieces of MDF and figured I'd compare notes with you before I get too far.

Joe L.

[ThomasW]

The audibility of higher end parts depends on the quality of the rest of the playback system.

[Dougie085]

Oh ok, well eventually I'll have an Outlaw 970 and Hypex UCD180 amplifiers. So would it be worth it for me to go the better quality stuff? and thanks for the answer I wasnt being an ass I just wasnt sure if anyone saw it.

[Brian Bunge]

Joe,

I think you misread his plans. The cabinet's external width is 28"W and internally is 26.5"W. His plans are based on the cabinet I built. The larger overall volume is due to my wanting a lower Q for the dual sealed 225's.

[Joe L.]

Joe,

I think you misread his plans. The cabinet's external width is 28"W and internally is 26.5"W. His plans are based on the cabinet I built. The larger overall volume is due to my wanting a lower Q for the dual sealed 225's.Brian,
Oops... you are right... I did mis-read the width
However... those dimensions make the enclosure even bigger.
The internal dimensions: 10 H x 26.5 W x 15.5 D.

That results in an internal volume of 4107.5 cubic inches or 2.377 cubic feet. (slightly over 400 cubic inches larger than the original posted plan)

I could increase the width of my center enclosure from 27.5 to 30 to match the overall volume you are describing. It would then internally be 12 H x 30 W x 16 D and have an internal volume of 4114 cubic inches (2.381 cubic feet)

Fortunately, I've only ripped some MDF to 10.5" and the pieces are all still 49" long. I can make the changes to the overall width very easily, but want to know the impact of the change on the overall frequency response.

The 30 inch width is not a problem. This center will replace my existing Audax HT center channel, and will be mounted above the screen in my theater. I do not have a lot of height available, but plenty of width.

It sounds like you have modeled this and thought it through. How does the additional volume affect the "Q" of the enclosure for the 225 woofers? What "Q" are you targeting? (Way back towards the beginning of this thread I think I saw the original "Q" was .77)

Joe L.

[ThomasW]

eventually I'll have an Outlaw 970 and Hypex UCD180 amplifiers. So would it be worth it for me to go the better quality stuffThe speakers have the ability to sound better with better XO parts. However, everything in the playback chain, not just the processor and amp impacts the SQ. So if you have the money certainly buy the best parts. You don't need the handmade North Creek inductors. But buying the 15 gauge aircore inductors from PE is a good idea.

[HMenke]

Joe sorry I missed your question - I had unsubscribed due to too many RS 3-way posts. I haven't started building anything yet; stilled stalled re: my soft-dome tweeter crossover issue. I have not modeled the box for the larger internal volume - I was just following along with Brian since he has more experience than I do.

If you'd like me to draw up alternate plans to your preferred dimensions I'd be glad to.

Henry

[Joe L.]

Joe sorry I missed your question - I had unsubscribed due to too many RS 3-way posts. I haven't started building anything yet; stilled stalled re: my soft-dome tweeter crossover issue. I have not modeled the box for the larger internal volume - I was just following along with Brian since he has more experience than I do.

If you'd like me to draw up alternate plans to your preferred dimensions I'd be glad to.

HenryI want to see Brian's response first, before I finalize my dimensions. Odds are the lower "Q" is desireable.

Thanks for the offer to draw up alternate plans. Hold off for now. Odds are I can work from the existing drawings as I'm doing all the work and not sending it off to a cabinet shop for construction.

Joe L.

[Brian Bunge]

The internal dimensions give you roughly 73L of volume before you subtract out the mid enclosure, bracing and any volume taken up by the drivers and crossover boards. When I settled on a dimensions I specifically worked up the volume of the mid enclosure, subtracted that from 73L, and then just sort of guessed what would be left over for the dual woofers once I subtracted out for everything else.

I guessimated for somewhere around 50L, which is what my Unibox simulation is saved as at the moment. With a decent amount of stuffing I should have a Q around .65, which is sounds much better in room to me that .7 or higher. Once you get up above .7 then you get a peak in the bass response and it will just be exaggerated even more if your speaker is mounted close to a wall, or on top of a TV, so I chose to go larger. This also will more closely match the Q of my towers, so I wanted some consistency in my front soundstage. Also, the lower Q gives a little better bass extension should I ever run the center with a lower crossover point than 80Hz.

[kgveteran]

How many ohms is the RS center :oops: .Is it as simple as measuring across the terminals :oops:

Thanx

[Joe L.]

I guessimated for somewhere around 50L (after subtracting the space occupied by the mid-enclosure and woofers), which is what my Unibox simulation is saved as at the moment. With a decent amount of stuffing I should have a Q around .65, which is sounds much better in room to me that .7 or higher. Once you get up above .7 then you get a peak in the bass response and it will just be exaggerated even more if your speaker is mounted close to a wall, or on top of a TV, so I chose to go larger.
...snip...
Also, the lower Q gives a little better bass extension should I ever run the center with a lower crossover point than 80Hz.Brian,
Thanks... I think that I'll follow in your lead and also go for the lower "Q." My center will be above the screen and near the ceiling. I do not want or need a peak in the bass response. I will probably also run with a 80 Hz crossover but could try 60Hz if the new center goes low enough. (I use a 80Hz crossover today with my Audax HT Center)

My dual sealed subwoofers are below the screen and built into the stage. Their response curve should easily blend with the new sealed center. (two Ascendant Avalanche 18" drivers, each in a 12.5 cubic foot sealed enclosure, also with a "Q" around .65, each displacing 6.5 liters of air.)

You can see in this picture (http://i3.tinypic.com/w0q45k.jpg) the space above the screen I have to work with. I plan on mounting the new W-M/T-W center inverted (midrange closest to the ceiling) by putting threaded inserts in the enclosure that I can use for eye-bolts. I'll then hang it by chains. Currently, I use chains to support a sloped shelf upon which the Audax HT center is sitting.

I really don't have a lot of height to spare, but can easily make the enclosure 30 inches wide. The new center will be slightly higher than the old, but I wont need the existing shelf if I can use the threaded inserts/eye-bolts. I figure it will fit in the same height as my current center channel.

Eventually I'll build new tower style left and right channel TMWW RS speakers to match the new center. This might take a while as I am not in a hurry and have pretty decent sound today. (I purchased the RS-225 woofers for them when they were on sale a month or so ago, but the matching left/right enclosures will probably be a winter project.)

Thanks again for your response. This project should be a lot of fun.

Joe L.

[MarkR]

How many ohms is the RS center :oops: .Is it as simple as measuring across the terminals :oops:

Thanx


Unfortunately it's not that easy, the imedance of a speaker changes as the frequency does. There are impedance sweeps posted on the first page of this thread.

[cjd]

This is a nominal 4ohm design.

[Brian Bunge]

Joe,

With your center so close to the ceiling it might require a bit of modification to the crossover to lower the baffle step compensation (BSC). I'm not sure which design you are planning on building, but I'd consider asking the designer how much BSC is built-in and what their recommendations are based on your mounting location.

[Vanders]

My current HT amp provides for 4 ohm mains but only 6 ohm centre & surrounds. Will this be an issue with this design? Any changes need to be made?

Mark

[Joe L.]

Joe,

With your center so close to the ceiling it might require a bit of modification to the crossover to lower the baffle step compensation (BSC). I'm not sure which design you are planning on building, but I'd consider asking the designer how much BSC is built-in and what their recommendations are based on your mounting location.Brian,
The photo in my prior post is slightly misleading because there is a lower portion of the ceiling in the room between the screen and the projector. The lower portion of ceiling covers a 12 inch steel "I" beam and air ducts for the heating/air conditioning.

The ceiling at the screen itself is 8 feet high and I think I'll benefit from the baffle step compensation as it was designed. The top edge of my current center is over 12 inches from the ceiling.

Attached is a photo showing the current Audax HT center and the shelf it sits on suspended from chains above the screen.

So.. I have more available height than I described earlier, but if I construct the enclosure much higher than 12 inches it will be partially blocked visually (and acoustically) from my rear row of seating.

Since I have no constraints horizontally, I'll simply make the wider as I described in my earlier post keeping the same internal volume.

Now, if any of the crossover designers want to comment and alert me to a possible problem, I won't complain. I have to figure that the position above the screen is not that unusual. Mt first reflection point on the ceiling is already acoustic tile above a cloth covered frame. That is a bit unique to my situation.

Joe L.

[cjd]

My current HT amp provides for 4 ohm mains but only 6 ohm centre & surrounds. Will this be an issue with this design? Any changes need to be made?

Mark

It may be an issue, it may not. An awful lot of content comes from the CC. A lot will depend on how loud you play things.

Any change would need to be to the amp - as in, upgrading. ;) My guess is these speakers will well be able to justify a better amp/receiver. Only reason I'm guessing is I don't know what you have.

C

[Vanders]

It may be an issue, it may not. An awful lot of content comes from the CC. A lot will depend on how loud you play things.

Any change would need to be to the amp - as in, upgrading. ;) My guess is these speakers will well be able to justify a better amp/receiver. Only reason I'm guessing is I don't know what you have.

C

Thanks C,

Amp is a Yamaha RX-V650 7.1 95W/channel.

I have been trying to avoid upgrading just yet. Comming before the "Minister for Finance & War" with that request is fraught with danger.

But out of curriosity what amps would you suggest - 70% HT 30% music.

I'm going to show my complete novice status here but is there any device to connect post HT amp to adjust impedance?

Mark

[dyazdani]

I have been trying to avoid upgrading just yet. Comming before the "Minister for Finance & War" with that request is fraught with danger.

You just need to work on your tactics... "upgrade" is a bad word, rephrase :lol:

I'm going to show my complete novice status here but is there any device to connect post HT amp to adjust impedance?

I'm sure you could - we can put people on the moon! I don't think it would have a favorable effect on the performance of the XO though. I'm just guessing here, I can't back it up with specifics.

[cjd]

I don't think it would have a favorable effect on the performance of the XO though. I'm just guessing here, I can't back it up with specifics.

Your guess is spot on. We can change the impedance, but it'll not be so helpful on response.

That said, if you're working at reasonable output levels, your amp should be up to the task.

And, if you take your time, show some pride in your work, make beautiful speakers, and your wife cranks it and causes the amp to auto-shut down for some reason? ;) Problem solved. :P That's likely the worst that'll happen. Keep the amp out so it can breathe (nothing right on top of it) and I think you'll have no trouble at all.

C

[kgveteran]

This is a nominal 4ohm design.

Thank you.I've been looking to upgrade amplifiers to handle these beasts.Of course DIY.The Hypex UCD180's look like a good place to start.I'm not done researching, but they show promise.

KG

[Dougie085]

The Hypex UCD180's look like a good place to start.

KG

Yea thats the way im going. Everyone seems to like them and they seem easy enough to build. All your building is the power supply :). I'm thinking of getting a reciever for a while though, anyone know of a reciever for about 400 bucks that would handle a 4 ohm load for a while? i was thinking of the Pioneer VSX-1015TX but i dont know?

[Dougie085]

How hard is Birch Plywood to work with? its been a while sence ive used wood and i want to use Baltic Birch Plywood to build my enclosures and stain them, but i want to put an MDF front baffle on it and paint it black and stain the sides. I think i can do it just not posative. Only thing im worried about really is making the sides all match up right. I want the edgest to come to a corner. But i want to roundover the edges of the front baffle. I should be ok just take my time i suppose.

[cjd]

Birch takes sharp tools, where you can sort-of do MDF with less sharp stuff. I would use sharp tools regardless for safety reasons.

You can get very nice sharp corners with it though.

I won't work with MDF at all for a variety of reasons.

And, not everyone likes the UCD modules that hears them, and not all implementations are the same, it seems. I'm walking a different road, of course. :)

C

[Dougie085]

Well, im concidering building a 2 channel chip amp kit to play with maybe i'll like it? although im having trouble finding the right kit? i asked this tech from digikey that i want about 150watts per channel at 4 ohms. but they cant seem to point me anywhere. So back to more reading and posting. And by sharp do you mean like a new table saw blade or what not?

[ssabripo]

Ok fellas....the CC building has begun: I dropped off the wood and parts at Chuck's place (in case you dont know, he has all the tools :D ). He just got a new table saw, and couldnt resist, so the prelim cuts started:

http://server5.ihostphotos.com/imgt/4ec6GefffT48cT7b2bc85W46360Tc814.jpg (http://server5.ihostphotos.com/show.php?id=4ec6GefffT48cT7b2bc85W46360Tc814)
http://server5.ihostphotos.com/imgt/f74ecG48cT0e6e0Tb39a22W9965cY3ff.jpg (http://server5.ihostphotos.com/show.php?id=f74ecG48cT0e6e0Tb39a22W9965cY3ff)
http://server5.ihostphotos.com/imgt/f74eG048T30e6e02T39a22W9965c0Gff.jpg (http://server5.ihostphotos.com/show.php?id=f74eG048T30e6e02T39a22W9965c0Gff)

We will do the rest this weekend. We plan on doing a rosewood veneer finish, if all goes well. I'm building the XO's this week....unfortunately, I had left out one of the 0.5mH coils, and had to pay $1.97 + $7.50 shipping! expensive boo boo

[BobEllis]

Not to stray too far off topic, but 150W/4 ohms is chip amp never never land. The LM3886 is current limited to 5A, so you need two in parallel to get to 100W average power (often mislabeled RMS power). Run at maximum rail voltage the pair would get you to 150W AVG, but would probably overheat or run you into protection due to the high current unless your heat sinks are massive. I'd use three or four in parallel (or a pair of LM4780s), and probably servos as shown in the bridge-parallel amp in the National application note. See www.chipamp.com among others for suitable amp kits without servos. (I'm just a customer, having built one for my daughter)

Since you'd have to make boards for four servos, you're getting up in complexity where you might as well go for an outstanding amp, like the Leach. With the right power supply, the Leach amp will give you around 250W into 4 ohms and sound a lot better than most chip amps. Boards are available from Professor Leach and his website is a good amp building tutorial. I built a 4 channel version as my first DIY amp project that worked the first time, and has been in daily use for the last 4 years. 8)

[stinems]

On J. Krutke's "tweeter mishmash" review (http://www.zaphaudio.com/tweetermishmash/), he says the Seas TDFC (H1189) is "exactly the same..." as the Seas TBFCG (H1212) with a few exceptions. Could the H1189 be considered a "drop-in" replacement for the H1212? What about the shielded version of the H1189, the H1210?

Is there a rule to qualify a tweeter as a "drop in" replacement for a particular crossover? ie, very similar impedance/phase curves?

I guess I was just wondering if my only option for a totally shielded version of this design would have to incorporate the RS28s?

[HMenke]

I'm sure you could - we can put people on the moon! I don't think it would have a favorable effect on the performance of the XO though. I'm just guessing here, I can't back it up with specifics.

This device would be called....an audio transformer! :B

[cjd]

Not to stray too far off topic, but 150W/4 ohms is chip amp never never land.

Not at all. :) Well, from a single chip you're correct, which as I reread your comment is what you're saying I believe. I just have to wire up a big trafo (650VA) to switch, fuse, hook up power supplies, wire up the boards, and I should have (presuming I have found all the PCB errors and corrected - core amp boards and power runs great, just haven't tested bridge board) over 150W@4ohm in a bridge/parallel configuration (SuSy too, so not just any bridge) capable of driving 2ohm. 2 LM4780's per (almost 4 3886's). The way I'm building it, there is TONS of flexibility to build up power around the core bridge, or even just single 3886 or 4780 boards.

Chipamp.com kits are OK, but a tad noisy. I have two from them.

C

[Dougie085]

And sorry that im the cause of the off topic chat here but what kits do you prefer? i saw National has pcb's but not component kits to go with them which id like to have rather then trying to find all the correct components?

[BobEllis]

Sounds like a fun project C. I hope you like it better than my point to point app-note LM4780. It gave up a lot of detail to my Leach, but it may have been my light heat sinking causing SPIKE to kick in. I have bigger sinks to rebuild it on, we'll see how it does.

I haven't fired up my chipamp.com kit, waiting for Par Metal to deliver the case.

/chipamp discussion in this thread

[cjd]

I have a thread here on my amp projects. ;) Feel free to dig it up and continue.

C

[HMenke]

Could the H1189 be considered a "drop-in" replacement for the H1212?I'm interested in this idea as well.

[jkrueger]

I am sure that you all get tired of "what if I just change this" questions, but.......I am trying to decide on my next project, and I am torn between the big RS 3-ways and the TMWW on this thread. I am interested in creating as full a range speaker as I can, and I am mainly restricted by baffle width (sounds stupid..I know) Could these TMWW be built with three woofers? (Like the B&W 803D) What would the changes to the plan be? Is it even possible? 8O

[Dougie085]

well that would mess up the impedance.

[Jim Holtz]

I am sure that you all get tired of "what if I just change this" questions, but.......I am trying to decide on my next project, and I am torn between the big RS 3-ways and the TMWW on this thread. I am interested in creating as full a range speaker as I can, and I am mainly restricted by baffle width (sounds stupid..I know) Could these TMWW be built with three woofers? (Like the B&W 803D) What would the changes to the plan be? Is it even possible? 8O

That would require a completely new crossover and would not make the bass any deeper. F3 is 49 Hz. sealed plus room gain gets you easily into the 30's. If you double the cabinet size and go ported. You have a full range speaker that will go into the 20's easily and do it loudly. (2) RS225's equal a 12" driver approximately.

Jim

[ssabripo]

Inner chamber is glued and we are gonna start on the front facia....Man, those drivers are HUGE!

[ssabripo]

Ok...XO number 1 done for the woofers. Whew, it took FOREVER!!! christ!

[Brian Walter]

I'm not an expert on laminated steel core inductors, but with air core, you should keep the axis of the inductors at right angles to each other or they can interact with one another if they are close enough to each other. I suspect that your inductors will do just that, so you may want to rotate the air core 90 degrees. I hope others will chime in on this and correct me if I'm wrong.

Brian Walter

[cjd]

Iron core inductors have to be aligned properly with the trash can. ;)

IIRC their field is parallel to the laminations, but I"m not sure, They're tougher to align, for sure. More than one reason to not use 'em.

C

[ssabripo]

According to this (http://www.troelsgravesen.dk/coils.htm), the coils should be aligned at 90 deg horizontally and perpendicular in the vertical realm:
http://www.troelsgravesen.dk/coils_files/coils_5.jpg

my setup is similar as that pic...the 4.7mH coil (the big green one) is setup in that same configuration as the .5mh coil (the small copper one)...

I don't understand how this is wrong, but if it is wrong, I would love to hear it....

[Dennis H]

No, you need to lay the air core down flat on the board to match that pic. What you have now is #3 (looked at on edge.) If you lay the air core down, you will have #7.

http://www.troelsgravesen.dk/coils_files/coils_9.gif

[ssabripo]

No, you need to lay the air core down flat on the board to match that pic. What you have now is #3 (looked at on edge.) If you lay the air core down, you will have #7.

http://www.troelsgravesen.dk/coils_files/coils_9.gif


Huh? I'm confused by your statement.

although the iron core coil (big green one) is not a circular one, the magnetic fields are still radiating outward since it is laying flat. So, lets say that Iron core "big green" coil is number1, and coil 2 is as is, then it seems I have #6 (or #7 if you consider the distance).

how is my setup like #3? wouldn't it look more like this:

[Dennis H]

Forget whether it's an iron core or an air core and whether it's short and fat or long and skinny. Just look at the direction of the circular windings, like follow a wire for one turn, and that will give you the orientation. In your last pic, both coils have the donut hole pointing toward the top of the pic and we're looking at the edge of the donut, albeit donuts with very different shapes.

Edit: well heck, Henry edited the pic so I will too. 1000 words and all that.... ;)

http://www.htguide.com/forum/attachment.php4?attachmentid=6217&stc=1

[HMenke]

Looking at the axis of the windings, they are circling in the same plane. I agree this represents condition #3. This is a high mutual inductance arrangement, i.e. the flux from each coil will couple into the other.

In the photo attached showing flux direction, the red area is the problem.

[ssabripo]

Looking at the axis of the windings, they are circling in the same plane. I agree this represents condition #3. This is a high mutual inductance arrangement, i.e. the flux from each coil will couple into the other.

In the photo attached showing flux direction, the red area is the problem.


yeah...that makes sense! DAMMIT! :banghead:

I'll have to figure out a way to remove the epoxy ....maybe with a razor or something. DARN!

anyways, Curt C just wrote and said to just lay it flat from where it is...it will hang out from the board, but who cares.

[kgveteran]

Hey S,
I ended up with the 4.7mH coil out on its own line away from the .50mH completely.Looks like hell, but you avoid the interaction.

BTW, those are done pretty neat.You do clean work, unlike my "done at the kitchen table ones"

[chasw98]

Hey kg:
I am helping sherv build this center channel and am wondering where you mounted the crossover components in your CC? Do you think you will ever need access to them in the future? Just looking for ideas on where to place them. Thanks.

Chuck

[ssabripo]

Hey S,
I ended up with the 4.7mH coil out on its own line away from the .50mH completely.Looks like hell, but you avoid the interaction.

BTW, those are done pretty neat.You do clean work, unlike my "done at the kitchen table ones"

Thanks man.

yeah, I want to keep it clean looking, so I put some effort on it. Plus, since Chasw98 is helping me the cabinet, and he is anal, then I have to keep my side clean too... :rofl:

anyways, I tried to cut the epoxy off, and nothing...I tried with a razor, and nothing....so I ended up cutting a piece out. Not as nice, but the surgery went so-so. here is the new configuration, and here is the tweeter XO too:

[dyazdani]

Looks great now!

[kgveteran]

Hey kg:
I am helping sherv build this center channel and am wondering where you mounted the crossover components in your CC? Do you think you will ever need access to them in the future? Just looking for ideas on where to place them. Thanks.

Chuck

I always have had a bad habit of mounting things as if they are the "end all".I hot glued them to the floor of the cabinet.I had to get back into them to do the L-pad and paid hell for it.You would be better off finding a more "removable" method than mine :oops:

While point to point soldering is great for sonics, i'd do the friction clips.It would have saved me some time.Upgrades are much easier also.

[ssabripo]

Ok.....FINALLY, the XO's are done. geezus that was time consuming! :M

here is the final look....notice I'm still missing a 0.5mh Coil, so I photoshoped it in there.. :lol: ...it should arrive today or tomorrow. We should be completed with the cabinet by sunday evening.

[chasw98]

I always have had a bad habit of mounting things as if they are the "end all".I hot glued them to the floor of the cabinet.I had to get back into them to do the L-pad and paid hell for it.You would be better off finding a more "removable" method than mine :oops:

While point to point soldering is great for sonics, i'd do the friction clips.It would have saved me some time.Upgrades are much easier also.


I agree. If I can keep my boy sherv from getting too anxious, I am going to find a servicable way of mounting them in the enclosure. :p:

[kgveteran]

Chasw98,
Servicability, I like that.Good luck!

[Brian Bunge]

I suggest just using that heavy duty velcro that they sell in the Crafts dept. at Wal-Mart. Trust me, the XO's won't go anywhere.

[HMenke]

here is the final look....notice I'm still missing a 0.5mh Coil, so I photoshoped it in there.. :lol: ...it should arrive today or tomorrow. We should be completed with the cabinet by sunday evening.Wow, super clean! Neat work = reliability. Way to go! :T

[chasw98]

I suggest just using that heavy duty velcro that they sell in the Crafts dept. at Wal-Mart. Trust me, the XO's won't go anywhere.

Thanks, Brian, good idea. They won't rattle with that soft furry stuff either. I was kind of hoping for some industrial hinge points like I've used in machines I've built in the past, but I don't have any around and time is of the essence. A man's life may be in danger :rofl:

[chasw98]

OK, the routing is done! Here are some pictures of my new Jasper Jig (courtesy of sherv) in action. And some more construction and dry fitting of the enclosure. The rest is up to sherv ;x(

http://i21.photobucket.com/albums/b297/chasw98/center%20channel/DSCN3713.jpg

http://i21.photobucket.com/albums/b297/chasw98/center%20channel/DSCN3718.jpg

http://i21.photobucket.com/albums/b297/chasw98/center%20channel/DSCN3719.jpg

http://i21.photobucket.com/albums/b297/chasw98/center%20channel/DSCN3720.jpg

http://i21.photobucket.com/albums/b297/chasw98/center%20channel/DSCN3723.jpg

http://i21.photobucket.com/albums/b297/chasw98/center%20channel/DSCN3725.jpg

[HMenke]

Schweet! What are the dimensions of this cabinet, Chuck? As shown on the first page of the thread?

Henry

[chasw98]

Schweet! What are the dimensions of this cabinet, Chuck? As shown on the first page of the thread?

Henry
Within a 32nd and square. Exactly as shown. I believe originally it called for 16 inch depth, but was shortened to 12 inches if you didn't need the extra bottom end.

[Rudy D]

Finally finish the TMWW's towers pictures can be seen here. http://www.villagephotos.com/pubbrowse.asp?folder_id=1663812 .

[Jim Holtz]

Finally finish the TMWW's towers pictures can be seen here. http://www.villagephotos.com/pubbrowse.asp?folder_id=1663812 .

They look very nice! I see you built the ported cabinet. Lets hear some listening impressions! :D

Jim

[ssabripo]

SAWEEEET!!!!!!!!! ;x( :T

good freakin job Chuck....heck, there aint much left for me to do but seal the final face and get started on the sanding/painting :lol:

the coil got here so I'm gonna have everything ready for tomorrow nite!! :T

[Rudy D]

They look very nice! I see you built the ported cabinet. Lets hear some listening impressions! :D

Jim

They sound great! Bass is deep, tight and has a really good punch to it. The midrange is very sweet. Voices sound really natural. the whole configuration blends real well. Imaging is good. ( and this is coming from a guy that owns a pair of ML Odysseys) Anyone still on the fence, needs to dive in. You will not be disapointed. as KG always says, "hats off to the guys here that cook up crossovers" To all the people I pinged for advise, thanks. so I'm off to enjoy,,,,,,,,,

[Brian Walter]

Rudy, those look really nice and I'm glad to hear you like the sound.

I'm in the middle of building the sealed version and I've got a question for you. From the photo's it's hard to tell for certain, but is the whole portion of the cabinet above the shelf between the RS150 and RS225 all one volume? That's what I'm about ready to do with mine, but I was wondering if maybe I should block off the very top portion behind the tweeter and keep it separate from the midrange. I'm still at the point where I could add a shelf brace at this location or make it a solid shelf. I was thinking the extra volume for the midrange might help cut down on the so called box sound. I'll probably be committed to however I'm going to do it by late afternoon or early evening. I'm heading out to the shop to route the baffles after I send off this message. I'll check back in this afternoon to see if anyone has any suggestions.

Off the the shop I go for my first attempt at using a Jasper Jig. I've used a homemade jig in the past, I'm hoping it will be easier to make repeatable cuts with the Jasper Jig.

Brian Walter

[dyazdani]

Off the the shop I go for my first attempt at using a Jasper Jig. I've used a homemade jig in the past, I'm hoping it will be easier to make repeatable cuts with the Jasper Jig.
It is very easy to use, just remember it is calibrated for a 1/4" bit, so take that into account if you use something else...

[Rudy D]

Rudy, those look really nice and I'm glad to hear you like the sound.

I'm in the middle of building the sealed version and I've got a question for you. From the photo's it's hard to tell for certain, but is the whole portion of the cabinet above the shelf between the RS150 and RS225 all one volume? That's what I'm about ready to do with mine, but I was wondering if maybe I should block off the very top portion behind the tweeter and keep it separate from the midrange. I'm still at the point where I could add a shelf brace at this location or make it a solid shelf. I was thinking the extra volume for the midrange might help cut down on the so called box sound. I'll probably be committed to however I'm going to do it by late afternoon or early evening. I'm heading out to the shop to route the baffles after I send off this message. I'll check back in this afternoon to see if anyone has any
suggestions.

Off the the shop I go for my first attempt at using a Jasper Jig. I've used a homemade jig in the past, I'm hoping it will be easier to make repeatable cuts with the Jasper Jig.

Brian Walter
Brian.
i went with what Dawaro provided. It is one volume. I did however use a good two hands full of Acousta-stuff, and teased it in to get rid of a little brightness. It works well now.
I have both Jasper Jigs. believe me it makes life a lot easier.

[ssabripo]

ok guys....here are some updates:

1. We spent last nite putting the XO's in, and doing final cuts/filling/etc. then we glued down all but one side:

[ssabripo]

2. Next, this morning we hooked up the drivers, and turned this puppy on!! :T The sound is pretty good, bute definitely different. The highs are bretty bright, the bass is nice and tight, and the voices are good but different. We compared them to CHuck's ascends and they definitely were different...not worst or much better, but different.

keep in mind that we just attached the last plate one before glueing so it wasn't complete yet!

[ssabripo]

3. Now the hard part starts....the finishing! First up, some major sanding, and then a couple of coats of sealer, then primer, then several coats of the paint! :(

but all and all, a good project...I'm sure once the cabinet is air tight, and the drivers break in a little, it will sound awesome